JP6391901B2 - Optical receiver module - Google Patents

Description

  The present invention relates to an optical receiver module having a plurality of lanes.

  In a wavelength division multiplexing optical communication system, an optical reception module that receives wavelength multiplexed light is used. Patent Document 1 proposes a wavelength demultiplexer applicable to a multi-wavelength integrated receiving module. In the wavelength separator of Patent Document 1, signal light including a plurality of wavelengths incident on the same optical path is wavelength-separated using a wavelength demultiplexing unit having a plurality of dielectric multilayer films having different bandpass characteristics. The wavelength-separated light of each wavelength is received by the output fiber array through the coupling lens.

  Patent Document 2 proposes a light receiving element having a distributed Bragg reflector (DBR) resonator structure.

JP 2011-209367 A JP 2001-308368 A

  When the light receiving element having the DBR resonator structure described in Patent Document 2 is used instead of the output fiber array of the wavelength separator described in Patent Document 1, the sensitivity at a specific wavelength is improved by the resonance effect of DBR. It is difficult to obtain high photosensitivity at all wavelengths simultaneously.

  The present invention has been made in view of the above, and an object thereof is to obtain an optical receiver module capable of obtaining high light receiving sensitivity at a plurality of wavelengths.

  In order to solve the above-described problems and achieve the object, an optical receiver module of the present invention includes a duplexer, a first optical component, and a second optical component. The demultiplexer wavelength-separates the wavelength-multiplexed incident light, and parallelizes a plurality of wavelengths of light including a first light having a first wavelength and a second light having a second wavelength. Exit to the lane. The first optical component includes a first lens that condenses the first light, and a first light receiving unit having a distributed reflection type resonator structure that receives the light collected by the first lens. Device. The second optical component has a second lens that collects the second light, and a second light receiving unit that has a distributed reflection type resonator structure that receives the light collected by the second lens. Device. The first along a first direction perpendicular to a first surface formed by the first light incident on the first optical component and the second light incident on a second optical component. The position of the first optical component is different from the position of the second optical component along the first direction.

  The optical receiving module according to the present invention has an effect that high receiving sensitivity can be obtained at a plurality of wavelengths.

1 is a top view showing an optical receiver module according to a first embodiment of the present invention. Sectional view along line AA in FIG. The figure which shows an example of the resonant wavelength characteristic of a light receiving element Side view showing the mounting position of each optical component in the height direction The figure which shows the positional relationship of the height direction of two optical components The figure which shows an example of the resonant wavelength characteristic of each light receiving element of Embodiment 1 FIG. 5 is a top view showing an optical receiver module according to a second embodiment of the present invention. Sectional view along line BB in FIG. The figure which shows the positional relationship of the height direction of each optical component of Embodiment 3 of this invention.

  Hereinafter, an optical receiver module according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a top view of the optical receiver module 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 2, the Y-axis direction is the height direction. FIG. 2 shows the arrangement position of each component for the light of wavelength λ2. The wavelength-multiplexed incident light 1 is incident on the optical receiving module 100 through the same optical path. Incident light 1 includes light of a plurality of different wavelengths. In the first embodiment, incident light includes light of four different wavelengths λ1, λ2, λ3, and λ4. In the first embodiment, λ1 <λ2 <λ3 <λ4. λ1 = 1295.56 nm, λ2 = 1300.05 nm, λ3 = 1304.58 nm, and λ4 = 1309.14 nm may be adopted to correspond to the standard 100GBASE-LR4 defined by IEEE.

  The optical receiver module 100 wavelength-separates the wavelength-multiplexed incident light 1 and parallelly divides the wavelength-separated light having a plurality of wavelengths λ1, λ2, λ3, and λ4 into a plurality of lanes 3-1, 3-2, 3-. 3 and 3-4, and optical components 4-1 to 4-4 on which light having wavelengths λ 1, λ 2, λ 3, and λ 4 emitted from the duplexer 2 is incident. The wavelength λ2 corresponds to the first wavelength in the claims, and any one of the wavelengths λ1, λ3, and λ4 corresponds to the second wavelength in the claims. The light of wavelength λ2 corresponds to the first light in the claims, and one of the light of wavelength λ1, the light of wavelength λ3, and the light of wavelength λ4 corresponds to the second light in the claims. . The optical component 4-1 includes a condenser lens 5-1 that collects light having a wavelength λ 1 and a light receiving element 6-1 that receives light having a wavelength λ 1 collected by the condenser lens 5-1. . The optical component 4-2 includes a condensing lens 5-2 for condensing light having a wavelength λ2, and a light receiving element 6-2 for receiving light having a wavelength λ2 collected by the condensing lens 5-2. . The optical component 4-3 includes a condensing lens 5-3 that condenses light having a wavelength λ3, and a light receiving element 6-3 that receives light having a wavelength λ3 collected by the condensing lens 5-3. . The optical component 4-4 includes a condensing lens 5-4 that condenses light having a wavelength λ4, and a light receiving element 6-4 that receives light having a wavelength λ4 collected by the condensing lens 5-4. . The light receiving elements 6-1 to 6-4 have a distributed reflection type (DBR) resonator structure, and photoelectrically convert received light. The optical component 4-2 corresponds to the first optical component in the claims, and any one of the optical components 4-1, 4-3, and 4-4 is the second optical component in the claims. Correspond. The condensing lens 5-2 corresponds to the first lens in the claims, and any one of the condensing lenses 5-1, 5-3, and 5-4 corresponds to the second lens in the claims. Correspond. The light receiving element 6-2 corresponds to the first light receiving element in the claims, and any one of the light receiving elements 6-1, 6-3, and 6-4 is the second light receiving element in the claims. Correspond.

  The optical receiving module 100 includes an amplifier 7 that amplifies each photoelectric conversion output of the light receiving elements 6-1 to 6-4, and light receiving element carriers 8-1 to 8 on which the light receiving elements 6-1 to 6-4 are mounted. -4 and a base carrier 9 on which the light receiving element carriers 8-1 to 8-4 are mounted on one side surface 9a. In the first embodiment, the base carrier 9 is made of metal. A base carrier 9 having a duplexer 2, optical components 4-1 to 4-4, an amplifier 7, and light receiving element carriers 8-1 to 8-4 is integrated in a metal package (not shown).

  Each component will be described in detail. The duplexer 2 wavelength-separates incident light 1 including light of four wavelengths λ1, λ2, λ3, and λ4. The duplexer 2 emits light of four wavelengths λ1, λ2, λ3, and λ4 that have been wavelength-separated in parallel to a plurality of lanes 3-1, 3-2, 3-3, and 3-4. The light having wavelengths λ1, λ2, λ3, and λ4 emitted from the duplexer 2 is collimated light or pseudo-collimated light. The height positions h of the outgoing lights of wavelengths λ1, λ2, λ3, and λ4 in the duplexer 2 are the same. As shown in FIG. 2, the light of wavelength λ2 is emitted from the duplexer 2 at the height position h. Lights of other wavelengths λ1, λ3, and λ4 are emitted from the duplexer 2 with the same height position h. The demultiplexer 2 can employ any configuration as long as the wavelength-division-multiplexed incident light 1 is wavelength-separated and the wavelength-separated light having a plurality of wavelengths is emitted in parallel to a plurality of lanes. . The wavelength demultiplexer disclosed in Patent Document 1 may be employed, or a wavelength demultiplexer having another configuration may be employed.

  The light receiving element carriers 8-1 to 8-4 are arranged in parallel on one side surface 9a of the base carrier 9. The light receiving elements 6-1 to 6-4 are mounted on the light receiving element carriers 8-1 to 8-4, respectively. The amplifier 7 is disposed on the upper surface of the base carrier 9. As shown in FIG. 2, one side surface 9 a of the base carrier 9 is inclined up and down so that the reflected light of the light receiving elements 6-1 to 6-4 does not return to the optical path of the incident light 1. The one side surface 9a corresponds to the first inclined surface in the claims.

  The light receiving elements 6-1 to 6-4 have a DBR resonator structure as described above. Here, DBR resonators having the same resonance wavelength characteristic are integrated in the light receiving elements 6-1 to 6-4. The DBR resonance wavelengths of the light receiving elements 6-1 to 6-4 are the longest of the four wavelengths λ1, λ2, λ3, and λ4 from the λ1 that is the shortest of the four wavelengths λ1, λ2, λ3, and λ4. It is designed to be a value up to λ4 which is the wavelength of the wave. FIG. 3 shows an example of the resonance wavelength characteristics of the light receiving elements 6-1 to 6-4. As shown in FIG. 3, in the first embodiment, the resonance wavelength characteristics are set so that all the light receiving elements 6-1 to 6-4 can obtain the peak sensitivity at the wavelength λ2.

  FIG. 4 is a diagram conceptually showing the mounting positions of the optical components 4-1 to 4-4. As shown in FIG. 4, the optical components 4-1 to 4-4 are arranged at different height positions. In other words, the optical components 4-1 to 4-4 have the first vertical to the first surface formed by the light of the wavelengths λ1, λ2, λ3, and λ4 incident on the optical components 4-1 to 4-4. Arranged at different positions along the direction. In the first embodiment, the first surface corresponds to a horizontal plane, and the first direction corresponds to a Y-axis direction that is a height direction. In FIG. 4, the circle at the center of the light receiving elements 6-1 to 6-4 indicates the light receiving unit 6 a that can transmit light. FIG. 5 is a diagram showing the positional relationship in the height direction between the optical component 4-1 and the optical component 4-2 in more detail. The arrangement of the optical component 4-2 is shown on the left side of FIG. 5, and the arrangement of the optical component 4-1 is shown on the right side of FIG.

  As shown in FIGS. 4 and 5, the center q1 of the condenser lens 5-1 and the center p1 of the light receiving part 6a of the light receiving element 6-1 in the optical component 4-1 are at the same height position. The same applies to the optical component 4-2, and the center q2 of the condenser lens 5-2 and the center p2 of the light receiving portion 6a of the light receiving element 6-2 are at the same height position. The same applies to the optical component 4-3, and the center of the condenser lens 5-3 and the center of the light receiving portion 6a of the light receiving element 6-3 are at the same height position. The same applies to the optical component 4-4, and the center of the condenser lens 5-4 and the center of the light receiving portion 6a of the light receiving element 6-4 are at the same height position.

  According to the DBR Bragg condition, the DBR resonance wavelength shifts to the short wavelength side as the incident angle with respect to the DBR increases. In other words, the DBR resonance wavelength shifts to the longer wavelength side as the incident angle with respect to the DBR becomes smaller. Therefore, the height position of the optical component 4-1 that receives the light of wavelength λ1 is set to the height position of the optical component 4-2 in which the DBR resonance wavelength is set to the wavelength λ2 that matches the incident light of wavelength λ2. Shift down by Δy for mounting. Thereby, the incident angle to the light receiving element 6-1 can be made larger than the incident angle to the light receiving element 6-2 without changing the height position of the incident light with respect to the optical component 4-1. As a result, the DBR resonance wavelength of the light receiving element 6-1 is qualitatively shifted to the short wave side. Therefore, the resonant wavelength of the light receiving element 6-1 is changed from λ2 to λ1 by shifting the height position of the optical component 4-1 downward from the position of the optical component 4-2 according to the difference between the wavelength λ1 and the wavelength λ2. Can be shifted.

  Since the wavelength λ3 is longer than the wavelength λ2, the light receiving element 6-3 is shifted by shifting the height position of the optical component 4-3 upward from the position of the optical component 4-2 according to the difference between the wavelength λ2 and the wavelength λ3. Can be shifted from λ2 to λ3. Similarly, by shifting the height position of the optical component 4-4 upward from the position of the optical component 4-2 according to the difference between the wavelength λ2 and the wavelength λ4, the resonance wavelength of the light receiving element 6-4 is changed from the wavelength λ2. The wavelength can be shifted to λ4.

  Next, the shift amount Δya, b between lanes will be described. The optical component in the lane corresponding to the wavelength λb is the first optical component, and the optical component in the lane corresponding to the wavelength λa is the second optical component. The shift amount Δya, b indicates the shift amount of the second optical component with respect to the height position of the first optical component. The wavelength λa and the wavelength λb are any one of the four wavelengths λ1, λ2, λ3, and λ4.

  n1 is the refractive index of air. n2 is the refractive index of the light receiving elements 6-1 to 6-4. F is the focal length of the condenser lenses 5-1 to 5-4. θ1, a is the incident angle to the light receiving element in the lane corresponding to the wavelength λa. θ2, a is a refraction angle inside the light receiving element in the lane corresponding to the wavelength λa. θ1, b is an incident angle to the light receiving element in the lane corresponding to the wavelength λb. θ2 and b are refraction angles inside the light receiving element in the lane corresponding to the wavelength λb.

Equations (1) and (2) hold from Snell's law.
n1 × sinθ1, a ＝ n2 × sinθ2, a… (1)
n1 × sinθ1, b = n2 × sinθ2, b (2)

Equation (3) is established from the Bragg reflection condition in DBR.
λb = λa (cosθ2, b / cosθ2, a) (3)

In addition, Equation (4) is established from the geometric relationship between the relative mounting positions of the optical components in the two lanes.
Δya, b / F ＝ tanθ1, b−tanθ1, a (4)

  Therefore, the shift amount Δya, b of the second optical component with respect to the first optical component is determined so as to satisfy the expressions (1) to (4). Specifically, by rearranging the formulas (1) to (4), the shift amount Δya, b is the first with the variables n1, n2, F, λa, λb and the incident angles θ1, b as variables. It can be expressed by the following conversion formula. Since the first conversion formula can be uniquely derived by organizing the formulas (1) to (4), disclosure of the first conversion formula is omitted. According to the first conversion equation, the positional relationship between the optical components 4-1 to 4-4 is mounted at a higher position as the wavelength becomes longer, as shown in FIG.

  As shown on the left side of FIG. 5, light having a wavelength λ2 is incident on the light receiving element 6-2 of the optical component 4-2 at an incident angle θ1,2 and is refracted at a refraction angle θ2,2. On the other hand, as shown on the right side of FIG. 5, light of wavelength λ1 is incident on the light receiving element 6-1 of the optical component 4-1, at an incident angle θ1,1, and refracted at a refraction angle θ2,1. Therefore, the shift amount Δy1,2 of the optical component 4-1 with respect to the optical component 4-2 is the above-described first variable using n1, n2, F, λ1, λ2 and the incident angle θ1,2 to the light receiving element 6-2 as variables. It can be calculated based on the following conversion formula.

  In the optical receiver module 100, when the resonance wavelength of all the light receiving elements 6-1 to 6-4 is set to a specific wavelength, there is a problem that the sensitivity deteriorates in a lane that is out of the resonance wavelength. Therefore, in the first embodiment, the mounting position of the optical component in the lane deviating from the resonance wavelength is shifted by the shift amount corresponding to the difference between the resonance wavelength and the wavelength of each lane. Thereby, the incident angle to the light receiving element of each lane changes, and the DBR resonance wavelength of each lane shifts.

  FIG. 6 shows an example of the resonance wavelength characteristics of the light receiving elements 6-1 to 6-4 when the mounting shown in FIG. 4 is performed. The light receiving element 6-1 mounted at a position lower than the light receiving element 6-2 has a resonance wavelength characteristic shifted so that peak sensitivity is obtained at the wavelength λ1. The light receiving element 6-3 mounted at a position higher than the light receiving element 6-2 has a shifted resonance wavelength characteristic so that peak sensitivity is obtained at the wavelength λ3. The light receiving element 6-4 mounted at a position higher than the light receiving element 6-3 has a shifted resonance wavelength characteristic so that peak sensitivity is obtained at the wavelength λ4. Thus, even when DBR light receiving elements set to the same resonance wavelength characteristic are used for all lanes, the height position of each DBR light receiving element is shifted according to the wavelength of each lane, so that all lanes It is possible to match the DBR resonance wavelength of the incident light with the wavelength of the incident light.

  When F = 0.7 mm, n1 = 1, n2 = 3.2, DBR design wavelength λ2 = 1300.05 nm, θ1,2 = 25 degrees, Δy1,2 which is the shift amount of the optical component 4-1 with respect to the optical component 4-2 = -72um, Δy3,2 = 87um which is the shift amount of the optical component 4-3 with respect to the optical component 4-2, and Δy4,2 = 195um which is the shift amount of the optical component 4-4 with respect to the optical component 4-2. Become. Δy is + in the upper direction of FIG. 2 and − in the lower direction.

  As described above, according to the first embodiment, when a light receiving element having the same resonance wavelength characteristic is used in each lane, the phenomenon that the DBR resonance wavelength changes according to the incident angle depending on the Bragg reflection condition is used. The mounting height positions of the optical components in the lane are made different. As a result, the light receiving sensitivity of each wavelength of light incident on the optical receiving module 100 can be made larger than before the shift of the height position. Also, by matching the DBR resonance wavelength with each signal wavelength, the slope of the sensitivity fluctuation with respect to the wavelength fluctuation becomes small, the DBR resonance wavelength fluctuation caused by the DBR refractive index fluctuation due to the temperature fluctuation, and the DBR resonance wavelength fluctuation for various mounting variations. It is possible to reduce the sensitivity fluctuation with respect to the above. Furthermore, the wavelength can be easily adjusted only by shifting the mounting height position of each optical component including the condenser lens and the light receiving element.

  In the first embodiment, 100GBASE LR4 having four wavelengths is taken as an example, but other arbitrary values may be adopted as the number of wavelengths, wavelength values, and wavelength intervals in the optical receiving module.

Embodiment 2. FIG.
In the first embodiment, the light receiving elements 6-1 to 6-4 are mounted on the side surfaces of the base carrier 9, but in the second embodiment, the light receiving elements 6-1 to 6-4 are mounted on the upper surface of the base carrier 9. FIG. 7 is a top view of the optical receiver module 200 according to the second embodiment of the present invention. FIG. 8 is a cross-sectional view taken along line BB in FIG. FIG. 8 shows the arrangement position of each component for the light of wavelength λ2. Constituent elements that achieve the same functions as those of the first embodiment are given the same reference numerals, and redundant descriptions are omitted.

  In the second embodiment, mirrors 10-1 to 10-4 that reflect incident light at right angles are arranged in each lane through which light of wavelengths λ1, λ2, λ3, and λ4 propagates. In the case of FIGS. 7 and 8, the mirror 10-1 reflects incident light in a direction inclined by 90 degrees from the incident direction between the duplexer 2 and the condenser lenses 5-1 to 5-4 in each lane. 10-4 are arranged. The light having the wavelength λ 1 reflected by the mirror 10-1 is incident on the optical component 4-1 including the condenser lens 5-1 and the light receiving element 6-1. As shown in FIG. 8, the light having the wavelength λ 2 reflected by the mirror 10-2 is incident on the optical component 4-2 including the condenser lens 5-2 and the light receiving element 6-2. The light of wavelength λ3 reflected by the mirror 10-3 is incident on an optical component 4-3 composed of a condenser lens 5-3 and a light receiving element 6-3. The light of wavelength λ4 reflected by the mirror 10-4 is incident on an optical component 4-4 composed of a condenser lens 5-4 and a light receiving element 6-4. The mirror 10-2 corresponds to the first mirror in the claims. Any one of the mirrors 10-1, 10-3, and 10-4 corresponds to the second mirror in the claims.

  In FIG. 7, the condenser lenses 5-1 to 5-4 are not shown, and only the light receiving elements 6-1 to 6-4 are shown. As shown in FIG. 8, a part of the upper surface of the base carrier 9 is a horizontal plane 9b, and the amplifier 7 is mounted on the horizontal plane 9b. A part of the upper surface of the base carrier 9 is an inclined surface 9c that is inclined in the X-axis direction, which is the front-rear direction, so that the reflected light of the light receiving elements 6-1 to 6-4 does not return to the optical path of the incident light. ing. The X axis is perpendicular to the Y axis. The X-axis is a horizontal direction and is parallel to a plurality of wavelengths of light emitted from the duplexer 2. The inclined surface 9c corresponds to the second inclined surface in the claims. On the inclined surface 9c of the base carrier 9, the light receiving elements 6-1 to 6-4 are arranged in parallel. In the second embodiment, the mounting positions of the optical components 4-1 to 4-4 in the X-axis direction are varied. In other words, the optical components 4-1 to 4-4 have the first vertical to the first surface formed by the light of the wavelengths λ1, λ2, λ3, and λ4 incident on the optical components 4-1 to 4-4. Arranged at different positions along the direction. In the second embodiment, the first surface corresponds to a vertical surface including the Y axis and an axis perpendicular to the Y axis and the X axis, and the first direction corresponds to the X axis direction. FIG. 7 shows that the mounting positions of the light receiving elements 6-1 to 6-4 in the X-axis direction are different. The amplifier 7 is rotated and arranged on the horizontal plane 9b of the base carrier 9 so that the longitudinal direction of the amplifier 7 is parallel to the arrangement direction of the light receiving elements 6-1 to 6-4. The light receiving elements 6-1 to 6-4 and the amplifier 7 are connected by a wire 15. The relationship between the wavelength of each lane and the shift amount in the X-axis direction of the optical components 4-1 to 4-4 is the same as that in the first embodiment, and a duplicate description is omitted.

  In the first embodiment, an optical receiving module can be configured without using a mirror member by mounting each light receiving element on the side surface of the base carrier 9. However, by changing the mounting position of each light receiving element in the height direction, an amplifier is provided. 7 and the wire length of each light receiving element varies between lanes. In the second embodiment, as shown in FIG. 7, the amplifier 7 is rotated and mounted in accordance with the mounting positions of the light receiving elements 6-1 to 6-4. The length of the wire 15 connecting 6-4 can be made constant. Thereby, the inductance component by each wire 15 can be made constant, and the signal transmission characteristic of each lane can be stabilized.

  In addition, you may arrange | position the mirrors 10-1 to 10-4 between the condensing lenses 5-1 to 5-4 and the light receiving elements 6-1 to 6-4 in each lane.

  As described above, according to the second embodiment, when a light receiving element having the same resonance wavelength characteristic is used for each lane, the phenomenon that the DBR resonance wavelength changes according to the incident angle depending on the Bragg reflection condition is used. The mounting positions of the optical components in the lane in the X-axis direction are made different. Thereby, it is possible to obtain the same effect as in the first embodiment. Further, the length of the wire 15 connecting the amplifier 7 and each of the light receiving elements 6-1 to 6-4 can be made constant.

Embodiment 3.
In the first embodiment, the light receiving elements having the same DBR resonance wavelength characteristic are used for all the lanes. However, in the third embodiment, the DBR resonance wavelength of each light receiving element is matched with the signal wavelength of each lane. That is, the DBR resonance wavelength characteristic of the light receiving element 6-1 in the lane in which the light of λ1 is transmitted is matched with the wavelength λ1, and the DBR resonance wavelength characteristic of the light receiving element 6-2 in the lane in which the light of λ2 is transmitted is the wavelength λ2. The DBR resonance wavelength characteristic of the light receiving element 6-3 in the lane in which the light of λ3 is transmitted is matched with the wavelength λ3, and the DBR resonance wavelength characteristic of the light receiving element 6-4 in the lane in which the light of λ4 is transmitted is Match with wavelength λ4. Thereby, ideally, the shift amount Δy of the mounting position of the optical components 4-1 to 4-4 becomes 0. However, in practice, the DBR resonance frequency is reduced due to film thickness variation, composition deviation, etc. during DBR fabrication. A problem arises that varies. Therefore, in the third embodiment, a phenomenon in which the DBR resonance wavelength varies depending on the incident angle depending on the Bragg reflection condition is used to compensate for the manufacturing variation in the DBR resonance wavelength of the light receiving elements 6-1 to 6-4.

  The configuration of the optical receiving module according to the third embodiment is the same as the configuration of the optical receiving module 100 shown in FIGS. 1 and 2, and redundant description is omitted. However, as described above, the DBR resonance wavelength of each light receiving element matches the signal wavelength of each lane. FIG. 9 is a diagram illustrating the mounting positions of the optical components 4-1 to 4-4. Light of wavelength λ1 is incident on the optical component 4-1, light of wavelength λ2 is incident on the optical component 4-2, and light of wavelength λ3 is incident on the optical component 4-3. The light of wavelength λ4 is incident on 4-4. Here, the DBR resonance wavelength of the light receiving element 6-2 coincides with the wavelength λ2, the DBR resonance wavelength of the light receiving element 6-1 is shifted to the longer wavelength side than the wavelength λ1, and the DBR resonance wavelength of the light receiving element 6-4 is It is assumed that the wavelength λ4 is shifted to the long wave side and the DBR resonance wavelength of the light receiving element 6-3 is shifted to the short wave side. A height position of the optical component 4-2 including the light receiving element 6-2 in which no deviation occurs is indicated by a broken line 20.

  Since the DBR resonance wavelength of the light receiving element 6-1 is shifted to the long wave side from the wavelength λ1, the height position of the optical component 4-1 is lower by Δy1 than the height position 20 when there is no shift. Shift and implement. In the light receiving element 6-3, the DBR resonance wavelength is shifted to the shorter wavelength side than the wavelength λ3. Therefore, the height position of the optical component 4-3 is raised by Δy3 with respect to the height position 20 when there is no shift. Shift and implement. In the light receiving element 6-4, the DBR resonance wavelength is shifted to the longer wave side than the wavelength λ4, so that the height position of the optical component 4-4 is lower by Δy4 than the height position 20 when there is no shift. Shift and implement.

  Next, the shift amount Δya for each lane will be described. The shift amount Δya is a shift amount corresponding to the shift of the resonance wavelength characteristic of the light receiving element in the lane corresponding to the wavelength λa. The shift amount Δya is a shift amount corresponding to the shift of the resonance wavelength characteristic of the light receiving element in the lane corresponding to the wavelength λb. The wavelengths λa and λb are any one of the four wavelengths λ1, λ2, λ3, and λ4.

  n1 is the refractive index of air. n2 is the refractive index of the light receiving elements 6-1 to 6-4. F is the focal length of the condenser lenses 5-1 to 5-4. θ1, a is the incident angle to the light receiving element before DBR resonance wavelength correction in the lane corresponding to the wavelength λa, θ2, a is the refraction angle in the light receiving element before DBR resonance wavelength correction in the lane corresponding to the wavelength λa, θ '1, a is the incident angle to the light receiving element after the DBR resonance wavelength correction in the lane corresponding to the wavelength λa, and θ'2, a is the refraction in the light receiving element after the DBR resonance wavelength correction in the lane corresponding to the wavelength λa. A corner. Δλa is the deviation of the DBR resonance wavelength.

Equations (5) and (6) are established from Snell's law.
n1 × sinθ1, a ＝ n2 × sinθ2, a… (5)
n1 × sinθ'1, a = n2 × sinθ'2, a (6)

Equation (7) is established from the Bragg reflection condition in DBR.
Δλa + λa = λa (cosθ'2, a / cosθ2, a) (7)

Further, the equation (8) is established from the geometric relationship before and after the correction of the DBR resonance wavelength of the lane corresponding to the wavelength λa.
Δya / F ＝ tanθ'1, a−tanθ1, a (8)

If the optical component in the lane corresponding to the wavelength λb is the first optical component, and the optical component in the lane corresponding to the wavelength λa is the second optical component, the second optical component relative to the height position of the first optical component. The shift amount Δya, b of the optical component is expressed by the equation (9).
Δya, b / F = (tanθ'1, b−tanθ1, b)
-(tanθ'1, a−tanθ1, a)… (9)

  Therefore, the shift amounts Δy1, Δy2, Δy3, Δy4 of the optical components 4-1 to 4-4 are determined so as to satisfy the above expressions (5) to (8). Specifically, by rearranging Equations (5) to (8), shift amounts Δy1, Δy2, Δy3, and Δy4 are variables for n1, n2, F, Δλa, λa, and incident angle θ1, a. It can be expressed by the second conversion formula. Since the second conversion formula can be uniquely derived by arranging the formulas (5) to (8), the disclosure of the second conversion formula is omitted.

  As described above, in the third embodiment, the optical components are shifted in accordance with the shift of the DBR resonance wavelength of the light receiving element in each lane, so that it is possible to correct the manufacturing error of the DBR resonance wavelength, It is possible to increase the light receiving sensitivity of light of each wavelength incident on the receiving module than before correction. Also, by matching the DBR resonance wavelength with each signal wavelength, the slope of the sensitivity fluctuation with respect to the wavelength fluctuation becomes small, the DBR resonance wavelength fluctuation caused by the DBR refractive index fluctuation due to the temperature fluctuation, and the DBR resonance wavelength fluctuation for various mounting variations. It is possible to reduce the sensitivity fluctuation to the above. Furthermore, the wavelength can be easily adjusted only by shifting the mounting position of each optical component composed of the condenser lens and the light receiving element.

  Also in the third embodiment, the second embodiment is applied, the mirrors 10-1 to 10-4 are arranged in each lane, and the optical components 4-1 to 4-4 are shifted in the X-axis direction. Also good.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

2 duplexer, 4-1 to 4-4 optical components, 5-1 to 5-4 condenser lens, 6-1 to 6-4
Light receiving element, 7 amplifier, 8-1 to 8-4 light receiving element carrier, 9 base carrier, 10-1 to 10-4 mirror, 15 wires, 100, 200 light receiving module.

Claims (9)

Demultiplexing wavelength-multiplexed incident light and emitting light of a plurality of wavelengths including a first light having a first wavelength and a second light having a second wavelength to a plurality of lanes in parallel And
1st light which has the 1st lens which condenses the said 1st light, and the 1st light receiving element which has the distributed reflection type resonator structure which light-receives the light condensed by the said 1st lens Parts,
Second light having a second lens for condensing the second light and a second light receiving element having a distributed reflection type resonator structure for receiving the light condensed by the second lens. Parts,
With
The first along a first direction perpendicular to a first surface formed by the first light incident on the first optical component and the second light incident on a second optical component. An optical receiver module, wherein a position of one optical component is different from a position of the second optical component along the first direction. The first light receiving element and the second light receiving element have resonance wavelength characteristics set to the first wavelength,
The second light receiving element is shifted in the first direction with respect to the first light receiving element so that a resonance wavelength characteristic of the second light receiving element matches the second wavelength. The optical receiver module according to claim 1, wherein:   The shift amount of the second light receiving element with respect to the first light receiving element is the first wavelength, the second wavelength, the refractive index of the first and second light receiving elements, the refractive index of air, and the The light receiving module according to claim 2, wherein the light receiving module is calculated based on an incident angle of the first light with respect to the first light receiving element. The first light receiving element has a resonance wavelength characteristic set at the first wavelength, the second light receiving element has a second resonance wavelength characteristic set at the second wavelength,
The first optical component is shifted along the first direction by a first shift amount corresponding to a shift in the resonance wavelength characteristic of the first light receiving element,
The second optical component is shifted and arranged along the first direction by a second shift amount corresponding to a shift in resonance wavelength characteristics of the second light receiving element. Optical receiver module. The first shift amount is the resonance wavelength characteristic shift of the first light receiving element, the first wavelength, the refractive index of the first light receiving element, the refractive index of air, and the first light receiving element. Calculated based on the incident angle of the first light before the shift arrangement,
The second shift amount is the resonance wavelength characteristic shift of the second light receiving element, the second wavelength, the refractive index of the second light receiving element, the refractive index of air, and the second light receiving element. The optical receiver module according to claim 4, wherein the optical receiver module is calculated based on an incident angle of the second light before the shift arrangement. A base carrier having a side surface on which the first light receiving element and the second light receiving element are mounted;
6. The optical receiver module according to claim 1, wherein the first direction is a height direction of the base carrier. 7.   The side surface has a first inclined surface inclined along a height direction of the base carrier, and the first light receiving element and the second light receiving element are mounted on the first inclined surface. The optical receiver module according to claim 6. A base carrier having an upper surface on which the first light receiving element and the second light receiving element are mounted;
A first mirror that reflects incident light at a right angle on a lane through which the first light propagates;
A second mirror that reflects incident light at a right angle on a lane through which the second light propagates;
6. The device according to claim 1, wherein the first direction is a horizontal direction and parallel to a plurality of wavelengths of light emitted from the duplexer. Optical receiver module. The upper surface of the base carrier has a second inclined surface inclined along the first direction of the base carrier;
The optical receiver module according to claim 8, wherein the first light receiving element and the second light receiving element are mounted on the second inclined surface of the base carrier.

Images