CN105572811B - Surface fixing type laser module - Google Patents

Abstract

The present invention provides a surface-fixed laser module, comprising a housing, a vertical cavity surface-emitting laser diode unit, at least one optical element, and a base accommodated in the housing and integrating the vertical cavity surface-emitting laser diode unit. The base has at least one surface transmission structure exposed outside the base and the housing for electronic signals to pass therethrough, and the optical element is located at an opening of the housing or at a location adjacent to the opening, and allows the laser beam provided by the vertical cavity surface-emitting laser diode unit to pass therethrough. The surface-fixed laser module of the present invention adopts the form of a surface-fixed element, which can effectively reduce the overall volume, and is suitable for application in electronic devices with a light, thin, short design, such as handheld devices and wearable devices.

Description

Surface Mounted Laser Module

technical field

The present invention relates to a laser module, in particular to a surface-fixed element type laser module.

Background technique

Please refer to FIG. 1 , which is a schematic perspective view of a partial structure of an existing laser module. The existing laser module 1 is in the form of a coaxial package (TO CAN), including a mask 11, a base 12, a laser diode 13, a photodiode 14, a heat sink 15, a first solder pin 16 and a second solder pin 17 , and the heat sink 15 and the photodiode 14 are fixed on the base 12, and the laser diode 13 is arranged on the heat sink 15; wherein, the laser diode 13 and the photodiode 14 are connected to the The first soldering leg 16 and the second soldering leg 17, and the first soldering leg 16 and the second soldering leg 17 respectively pass through the base 12 downwards and protrude outwards, which are used to pass through an external circuit board (Fig. not shown) and then soldered on the circuit board, so that electronic signals can be transmitted between the laser module 1 and the circuit board.

Furthermore, the cover 11 is arranged on the base 12 to cover the laser diode 13, the photodiode 14 and the heat sink 15, and the cover 11 has an opening 111 for a collimating lens to be placed on it; The laser diode 13 can provide the laser beam L1 when receiving power through the first welding leg 16, and most of the laser beam L11 will travel toward the opening 111 of the mask 11, and output out after passing through the collimator lens 10, and A small part of the laser beam L12 is projected towards the direction of the photodiode 14 for photodetection by the photodiode 14; The test signal is transmitted to the circuit board through the second solder pin 17 for use in subsequent related control programs.

It is particularly noted that in the past, in order to weld the laser module 1 on the circuit board, the laser module 1 needs to be additionally provided with a first soldering leg 16 and a second soldering leg 17 for passing through the circuit board; however, such soldering leg There is a minimum size limit, otherwise the solder pins will be easily broken due to external force, but such a packaging method makes the laser module 1 unable to be effectively miniaturized, let alone apply it to light, thin, and Short design on electronic devices.

Furthermore, when the existing laser module 1 integrates optical elements (such as the collimator lens 10 ), it often takes up too much space due to its own structural limitations, which is also one of the reasons why the miniaturization requirement cannot be met. In addition, most of the existing laser modules 1 are mainly based on a single light source, so they cannot meet the needs of multiple light sources or multiple wavelengths required by today's electronic equipment, thereby limiting the rapid development of electronic equipment such as handheld devices and wearable devices. ; According to the above description, the existing laser module 1 still needs to be improved.

Contents of the invention

One of the technical problems to be solved by the present invention is to provide a surface mounted device (SMD) type laser module for the above-mentioned deficiencies in the prior art, so that the overall volume of the electronic device used can be reduced. Because the laser module integrates diffractive optical elements, it has the effect of laser diffraction projection; in addition, the laser module can also have multiple vertical cavity surface-emitting laser diode units, so it can meet the needs of today's electronic equipment. The demand for multiple light sources or multiple wavelengths accelerates the development of electronic devices such as handheld devices and wearable devices.

The technical solution adopted by the present invention to solve the technical problem is to provide a surface-mounted laser module, which includes a housing, a base, and a vertical-cavity surface-emitting laser diode (VCSEL) unit And at least one optical element, the housing has an opening; the base is accommodated in the housing and has at least one surface transmission structure exposed to the base and the housing for at least one electronic signal to pass through; the vertical The resonant cavity surface-emitting laser diode unit is fixed on the base and provides at least one laser beam; the at least one optical element is fixed on the housing and is located at the opening or a vicinity of the opening; wherein, the vertical resonant cavity surface-emitting A type laser diode unit is located between the base and the at least one optical element, and a first part of the at least one laser beam is projected onto the at least one optical element and outputted outward after being optically processed by the at least one optical element .

Preferably, the surface-mounted laser module further includes at least one photodiode unit disposed on the base; wherein, a second part of the at least one laser beam is projected onto the photodiode unit for the light Sense diode unit for detection.

Preferably, a central laser beam of the at least one laser beam travels from a center of a light-emitting area of the vertical cavity surface-emitting laser diode unit toward an optical center of the at least one optical element.

Preferably, the at least one optical element includes a collimating optical element for collimating the laser beam passing therethrough.

Preferably, the at least one optical element further includes a diffractive optical element, configured to shape the laser beam passing through the collimating optical element and output it to the outside.

Preferably, the distance between a first optical axis of the collimating optical element and a second optical axis of the diffractive optical element is less than 0.2 mm.

Preferably, the included angle between a first optical axis of the collimating optical element and a second optical axis of the diffractive optical element is less than 2.5 degrees.

Preferably, the collimating optical element and the diffractive optical element are integrated into a single optical structure.

Preferably, an effective focal length f of the collimating optical element satisfies the following condition: f<1.5 mm.

Preferably, a numerical aperture N.A. of the collimating optical element satisfies the following condition: N.A.<0.5.

Preferably, the surface-mounted laser module further includes another vertical cavity surface-emitting laser diode unit, and the collimating optical element is used to collimate the vertical cavity surface-emitting diode unit and the other vertical cavity surface-emitting diode unit. Multiple laser beams provided by a resonant cavity surface-emitting laser diode unit.

Preferably, an anti-reflection coating is coated on the at least one optical element.

Preferably, the at least one surface transfer structure includes at least one electrical pad or at least one pin.

Preferably, the vertical cavity surface-emitting laser diode unit includes multiple laser diode chips to provide multiple laser beams.

Preferably, the surface-mounted laser module further includes a photodiode unit and a light guide element disposed outside the base, and the light guide element is used to guide a second part of the at least one laser beam to The photodiode unit travels for detection by the photodiode unit.

In the present invention, the laser module is designed in the form of a surface mounted device (SMD), which can effectively reduce the overall volume, so it can be applied to light, thin, and short electronic devices such as handheld devices and wearable devices; And because the present invention integrates the diffractive optical element into the surface-fixed laser module, the effect of laser diffraction projection can be brought into play; in addition, the laser module of the present invention can also have multiple vertical resonant cavity surface-emitting laser diode units, Therefore, the requirement of multi-light sources or multi-wavelengths required by today's electronic devices can be met, thereby accelerating the development of electronic devices such as handheld devices and wearable devices.

Description of drawings

Figure 1: A schematic diagram of a part of the existing laser module.

FIG. 2 is a schematic diagram of the appearance structure of a first preferred embodiment of the surface-mounted laser module of the present invention.

Fig. 3 is a three-dimensional exploded schematic diagram of the surface-mounted laser module shown in Fig. 2 .

Fig. 4: It is a partial structural front view of the surface-fixed laser module shown in Fig. 2 .

FIG. 5 is a structural schematic diagram of a second preferred embodiment of the surface-mounted laser module of the present invention.

FIG. 6 is a structural schematic diagram of a third preferred embodiment of the surface-mounted laser module of the present invention.

Detailed ways

Please refer to FIGS. 2 to 4. FIG. 2 is a schematic diagram of the appearance structure of the surface-mounted laser module in a first preferred embodiment of the present invention. FIG. 3 is a three-dimensional exploded schematic diagram of the surface-mounted laser module shown in FIG. 2 . FIG. 4 is a partial structural front view of the surface-mounted laser module shown in FIG. 2 . The surface-mounted laser module 2 includes a housing 21, a base 22, a vertical-cavity surface-emitting laser diode (VCSEL) unit 23, and two photodiode (PD) units 24. And a plurality of optical elements 25, and the base 22 is accommodated in the housing 21, which carries one or more vertical cavity surface-emitting laser diode units 23 and photodiode units 24, and can provide a flat surface or have One or more vertical resonator surface-emitting laser diode units 23 and photodiode units 24 are fixed in the recesses on the bottom surface. Wherein, the base 22 has a plurality of surface transmission structures 221 exposed outside the base 22 and the housing 21, the thickness of which is much smaller than the thickness of the base 22 and the housing 21, and can be soldered on the circuit board through solder paste ( Not shown in the figure), so that the electronic signal from the surface-mounted laser module 2 can be transmitted into the circuit board through the surface transmission structure 221, and the electronic signal from the circuit board can also be transmitted into the circuit board through the surface transmission structure 221. Surface fixed laser module 2. Preferably, the surface transmission structure 221 may be in the form of an electrical pad or a pin, but not limited thereto. Also, although the base 22 shown in the figure is in the form of a cuboid, it is not limited thereto, and can be designed according to actual needs in application.

Moreover, the housing 21 and/or the base 22 can provide heat dissipation. The housing 21 has an opening 211, wherein the circular shape and size of the opening 211 (not limited to those shown in the figure) can also be other shapes and sizes, mainly The laser beam in the non-transparent housing 21 can pass through to the outside world. Furthermore, the plurality of optical elements 25 are arranged at the opening 211 or near the opening 211, and the vertical resonator surface-emitting laser diode unit 23 includes a laser diode chip 231, which is located on two photosensitive cells in the horizontal direction. The diode units 24 are located between the base 22 and the plurality of optical elements 25 in the vertical direction. Wherein, the vertical resonator surface-emitting laser diode unit 23 can provide multiple laser beams L2 after receiving power (such as receiving power through the surface transmission structure 221), and the first part (main part) of the laser beams L2 The light beam L21 is directed toward The opening 211 of the casing 21 advances, and then the plurality of optical elements 25 are optically processed and output to the outside; in addition, the second part (secondary part) beam L22 of the laser beams L2 then goes to the photodiode unit 24 Direction projection for the photodiode unit 24 to perform light detection, and the photodiode unit 24 will generate detection signals during the detection process, and these detection signals will be transmitted outward through the surface transmission structure 221 for the Subsequent related control procedures are used.

In this preferred embodiment, the plurality of optical elements 25 include a collimating optical element 251 and a diffractive optical element 252 (diffractive optical element, DOE), and the collimating optical element 251 is fixed on the opening 211 of the casing 21 , and the diffractive optical element 252 is located above the collimating optical element 251 and fixed at the groove 212 on the casing 21 . Among them, the collimating optical element 251 is used to collimate the laser beam L21 emitted from the vertical cavity surface-emitting laser diode unit 23, so that the laser beam L21 passing through the collimating optical element 251 is incident on the diffractive optical The diffractive optical element 252 is used to shape the laser beam L21 passing through the collimating optical element 251 and output it to the outside. Generally speaking, through the texture design of the diffractive optical element 252, the surface-fixed laser module 2 can become a generator of a specific structured light source, and can play the effect of laser diffraction projection; however, the diffractive optical element itself is in the technical field It is well known to those of ordinary skill in the art, and will not be described in detail here.

Also, in this preferred embodiment, the collimating optical element 251 and/or the diffractive optical element 252 can be coated with an anti-reflection coating (anti-reflection coating) to improve light transmittance, and the collimating optical element 251 The effective focal length f and numerical aperture N.A. meet the following conditions respectively: f<1.5 millimeters, N.A.<0.5, but not limited to the above; wherein, the optical axis 2511 of the collimating optical element 251 and the optical axis 2521 of the diffractive optical element 252 ( The offset between the second optical axes) is preferably less than 0.2 mm, and the included angle between the optical axis 2511 of the collimating optical element 251 and the optical axis 2521 of the diffractive optical element 252 is preferably less than 2.5 degrees. Preferably, but not limited thereto, a central laser beam L211 in the laser beams L21 is directed from the center of the light-emitting area of the vertical resonator surface-emitting laser diode unit 23 toward the optical center 2512, 2522 (the front and rear direction of light passing through these points is unchanged).

Also, in another preferred embodiment, the collimating optical element 251 and the diffractive optical element 252 are integrated into a single optical structure; optionally, a plate is arranged between the collimating optical element 251 and the diffractive optical element 252, and In order to overcome the error caused by the integration of the collimating optical element 251 and the diffractive optical element 252, the plate body is made of a material different from that of the collimating optical element 251 and the diffractive optical element 252, so as to correct the penetration direction of the laser beam L21 and Improve light penetration.

Of course, the above is only an example, and those skilled in the art can make any equivalent design changes according to actual application requirements. For example, although the surface-fixed laser module in the above-mentioned embodiment only includes a single vertical resonant cavity The surface-emitting laser diode unit 23 can be modified as shown in FIG. 5 . Please refer to FIG. 5 , which is a schematic diagram of a partial structure of a surface-mounted laser module in a second preferred embodiment of the present invention. The surface-mounted laser module of the second preferred embodiment is roughly similar to that described in the aforementioned first preferred embodiment, and will not be described in detail here; and this preferred embodiment is the same as the aforementioned preferred embodiment. The difference is that the base 22 includes a plurality of vertical cavity surface-emitting laser diode units 23 and a plurality of photosensitive diodes 24 for proper configuration, and the multiple vertical cavity surface-emitting laser diode units 23 provide A plurality of laser beams L21 are collimated by the collimating optical element 251 and then incident on the diffractive optical element 252; similarly, when the vertical cavity surface-emitting laser diode unit 23 has multiple laser diode chips, a similar method can be used to achieve purpose of the present invention. Of course, the number of collimating optical elements 251 is not limited. For example, a surface-mounted laser module may include a plurality of collimating optical elements 251 corresponding to these resonant cavity surface-emitting laser diode units 23 .

For another example, although the photodiode units 24 of the surface-mounted laser module in the above embodiments are all disposed on the base 22 , the design can be changed as shown in FIG. 6 . Please refer to FIG. 6 , which is a schematic structural diagram of a third preferred embodiment of the surface-mounted laser module of the present invention. The surface-mounted laser module of this preferred embodiment is roughly similar to those described in the first and second preferred embodiments above, and will not be described in detail here; and this preferred embodiment and the aforementioned preferred embodiments The difference is that the photodiode unit 24 is arranged on the outside of the base 22, and the surface-mounted laser module further includes a light guide element 27 for guiding the beam when a part of the laser beam L2 is incident on it. L2 travels toward the photodiode unit 24, so that the photodiode unit 24 disposed outside the base 22 can perform light detection. As described in the foregoing embodiment, the photodiode unit 24 will generate detection during the detection process. The test signal is used for subsequent related control programs.

In this preferred embodiment, the photodiode unit 24 can be a planar type photodiode unit or a dome type photodiode unit, and the light guide element 27 can be a light reflection The element or a diffractive optical element (DOE) can be designed as a film or formed by coating. However, the above is only an example, and the form of the photodiode unit, the position, form and formation method of the light guide element are not limited to the above.

In particular, the present invention designs the laser module as a surface mounted device (SMD), which can effectively reduce the overall volume, so it can be applied to hand-held devices, wearable devices, and other light, thin, and short designs. electronic equipment; and because the present invention integrates diffractive optical elements into the surface-fixed laser module, the effect of laser diffraction projection can be brought into play; in addition, the laser module of the present invention can also have multiple vertical resonant cavity surface-firing Therefore, the laser diode unit can meet the multi-light source or multi-wavelength requirements required by today's electronic equipment, thereby accelerating the development of electronic equipment such as handheld devices and wearable devices.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the claims of the present invention. Therefore, all other equivalent changes or modifications that do not deviate from the spirit disclosed in the present invention should be included in this disclosure. inventions within the scope of patent protection.

Claims (13)

1. A surface fixed laser module, characterized in that it comprises: a housing having an opening; a base, accommodated in the housing and having at least one surface transmission structure exposed to the base and the housing for at least one electronic signal to pass therethrough; A vertical cavity surface-emitting laser diode unit is fixed on a horizontal surface of the base and provides at least one laser beam; at least one optical element fixed to the housing and located at or in a vicinity of the opening; and at least one photodiode unit is disposed on the horizontal surface of the base; Wherein, the vertical resonant cavity surface-emitting laser diode unit is located between the base and the at least one optical element, and a first part of the at least one laser beam is projected onto the at least one optical element and received by the at least one optical element After optical processing, the element is output to the outside, and a second part of the at least one laser beam is projected to the photodiode unit for detection by the photodiode unit. 2. The surface-mounted laser module according to claim 1, wherein a central laser beam in the at least one laser beam is emitted from a center of a light-emitting area of the vertical resonator surface-emitting laser diode unit Traveling towards an optical center of the at least one optical element. 3. The surface-mounted laser module as claimed in claim 1, wherein the at least one optical element comprises a collimating optical element for collimating the laser beam passing therethrough. 4. The surface-mounted laser module according to claim 3, wherein the at least one optical element further comprises a diffractive optical element, which is used to shape the laser beam passing through the collimating optical element and direct it to external output. 5. The surface-mounted laser module of claim 4, wherein a distance between a first optical axis of the collimating optical element and a second optical axis of the diffractive optical element is less than 0.2 mm. 6. The surface-mounted laser module according to claim 4, wherein the angle between a first optical axis of the collimating optical element and a second optical axis of the diffractive optical element is less than 2.5 degrees . 7. The surface-mounted laser module according to claim 4, wherein the collimating optical element and the diffractive optical element are integrated into a single optical structure. 8. The surface-mounted laser module according to claim 3, wherein an effective focal length f of the collimating optical element satisfies the following condition: f<1.5 mm. 9. The surface-mounted laser module according to claim 3, wherein a numerical aperture N.A. of the collimating optical element satisfies the following condition: N.A.<0.5. 10. The surface-mounted laser module according to claim 3, wherein the surface-mounted laser module further comprises another vertical cavity surface-emitting laser diode unit, and the collimating optical element is used for Collimating multiple laser beams provided by the vertical cavity surface-emitting diode unit and the other vertical cavity surface-emitting laser diode unit. 11. The surface-mounted laser module according to claim 1, wherein an anti-reflection film is coated on the at least one optical element. 12. The surface-mounted laser module of claim 1, wherein the at least one surface transmission structure comprises at least one electrical pad or at least one pin. 13. The surface-mounted laser module according to claim 1, wherein the vertical cavity surface-emitting laser diode unit comprises a plurality of laser diode chips to provide a plurality of laser beams.