CN102457014A - Laser source - Google Patents

Abstract

The present invention relates to a laser source having a structure for effectively suppressing the generation of a light surge when pulsed light output is resumed after a pause. The laser source includes: a first light source that outputs light with a first wavelength as pulsed light; a second light source that outputs light with a second wavelength different from the first wavelength; an optical amplification fiber as an optical amplifier, for The pulsed light output from the first light source and the light output from the second light source are amplified; and a control unit controls the light output from the second light source based on the light output from the first light source. The first light source has an ON state in which output of pulsed light starts and continues repeatedly at a fixed period, and an OFF state in which output of pulsed light is suspended for a duration not less than the fixed period. The control unit controls the second light source to output light to the optical amplifying fiber during the duration that the first light source is in an OFF state so as to suppress a rise in population inversion of the rare earth element added in the optical amplifying fiber.

Description

laser source

technical field

The present invention relates to a high-output laser source that outputs pulsed light amplified by using an optical amplifier, and is suitable for processing applications, medical applications, and the like.

Background technique

In many fields such as laser processing, medical treatment, metrology, etc., pulsed lasers with short pulse width and high pulse peak power allowing faster repetition rates are required. In the field of laser processing, pulsed laser is usually realized by Q-switching. However, in Q-switched pulsed laser sources, there are limitations in generating shorter pulses and it is also difficult to achieve fast repetition rates because the pulse width is equal to the duration of the light traveling back and forth in the optical resonator many times. For this reason, it is being considered to use a laser source of an MOPA (Master Oscillator Power Amplifier) system in which a seed light source is a pulse-modulated semiconductor laser or the like, and an optical amplifier is located downstream thereof. It is known that when the MOPA system is used for a laser source, the effect is that high gain and stable diffraction are easily achieved by constituting the optical amplifier section with an optical fiber amplifier in which the optical amplification medium is an optical fiber doped with a rare earth element. Limited beam quality.

However, when the pulsed operation is suspended in a pulsed laser source using the MOPA system, the suspension of the pulsed light output from the seed source increases the population inversion to a limit in the optical fiber that is included in the fiber amplifier and Optical amplification medium doped with rare earth elements. Therefore, an optical surge in which the optical power of the output light temporarily increases can be generated once the pulse operation is restarted. As a method for preventing the workpiece from being irradiated with the laser light of the resulting light surge, a method of stopping the pulsed laser light after restarting the output is being studied, for example, as disclosed in Japanese Patent Application Laid-Open No. 2001-358087.

Contents of the invention

The present inventors have studied the above-mentioned conventional laser light sources in detail, and as a result, have found the following problems.

That is, the generation of the above-mentioned light surge may also affect something other than the workpiece to be irradiated with laser light. For example, the generation of an optical surge can cause failure of the laser source. It is also conceivable to adopt a method of terminating the operation of the optical fiber amplifier, but it is difficult to achieve stable operation in a short time because the warm-up operation before thermal equilibrium takes a certain amount of time in the process of pumping the optical fiber amplifier again. As described above, it is desirable to provide a laser source capable of suppressing the generation of light surge after restarting and stably outputting pulsed light of constant intensity in the case of suspending the output of pulsed light from the laser source using the MOPA system .

The present invention is made in order to solve the above-mentioned problems. It is an object of the present invention to provide a laser light source configured to effectively suppress generation of light surges upon restart after suspending output of pulsed light.

In order to achieve the above object, a laser source according to the present invention includes a first light source, a second light source, an optical amplifier and a control unit. The first light source outputs light having a first wavelength as pulsed light. The second light source outputs light having a second wavelength different from the first wavelength. The optical amplifier amplifies the light output from the first light source and the light output from the second light source. The control unit controls the light output from the second light source based on the light output from the first light source.

Particularly, in the laser light source according to the present invention, the first light source has an ON (turn-on) state that starts and continues repeatedly outputting pulsed light at a fixed cycle, and pauses pulses during a duration not less than the fixed cycle The OFF state of the light output. The control unit controls the second light source to output light to the optical amplifier during the duration that the first light source is in an OFF state.

In the laser source according to the present invention as described above, for example, when a fiber amplifier is used as an optical amplifier, when the first light source is in the OFF state (in this state, the pulse light output from the first light source is not less than the While being paused for a fixed period of time), light from the second light source is output to an optical amplification fiber. In this case, the population inversion is suppressed in the optical amplification included in the optical amplifier, so that when the first light source becomes ON state (in which state starts and continues to repeat from the first light source with a fixed cycle When outputting pulsed light), it can effectively prevent the generation of light surge.

The laser source according to the invention may also comprise a filter. The optical filter transmits light having the first wavelength but blocks light having a second wavelength in the amplified light output from the optical amplifier. When the laser source further includes the optical filter as described above, it is possible to effectively prevent the light output from the second light source and amplified by the optical amplifier from being output to the outside of the laser source.

The control unit may be configured to control the second light source to suspend light output when the state of the first light source changes from OFF to ON or during the duration of the first light source being in the ON state. When the light output from the second light source is suspended while the first light source is in the ON state as described above, laser light can be output to the outside of the laser light source without suppressing the peak power of pulsed light output from the first light source.

The optical amplifier is preferably configured to include an optical fiber doped with optical amplification elements as an optical amplification medium. The optical amplifier is preferably configured such that the rise time of light output from the second light source is set to a time of 50%-200% of the time the pumped state of the optical amplifying element exists.

Description of drawings

1 is a view showing the structure of a first embodiment of a laser light source according to the present invention;

FIG. 2 is a view showing the LWPF 26 included in the laser light source ( FIG. 1 ) according to the first embodiment;

3A and 3B are views showing a multiplexer 23 included in the laser light source (FIG. 1) according to the first embodiment;

4A and 4B are views showing laser output from the laser light source (FIG. 1) according to the first embodiment;

FIG. 5 is a view showing laser processing by the laser source (FIG. 1) according to the first embodiment;

Fig. 6 shows the presence/absence of scanning in the X-axis direction and the Y-axis direction with a galvano scanner and the presence/absence (ON state and OFF state) of laser output from the first light source 17 and the second light source 21 A view of examples of relationships between situations;

7 is a graph showing the presence/absence of scanning in the X-axis direction and the Y-axis direction with a galvano scanner and the presence/absence (ON state and OFF state) of laser output from the first light source 17 and the second light source 21. a view of another example of the relationship between the situations; and

Fig. 8 is a view showing the structure of a second embodiment of a laser light source according to the present invention.

Detailed ways

Hereinafter, an embodiment of a laser light source according to the present invention will be described in detail with reference to FIGS. 1 , 2 , 3A to 4B , and 5 to 8 . In the description of the drawings, the same or corresponding components are denoted by the same reference symbols, and repeated descriptions are omitted.

(first embodiment)

A first embodiment of the laser light source according to the present invention will be described. FIG. 1 is a view showing the structure of a laser light source 1 according to a first embodiment. As shown in Figure 1, laser source 1 comprises optical amplification fiber 11,12, pumping light source 13,14, combiner 15,16, first light source 17, optical isolator 18,20, bandpass filter 19, the second Light source 21 , control unit 22 , WDM (Wavelength Division Multiplexing) coupler 23 , end cap 24 , lens 25 and LWPF (Long Wavelength Transmission Filter) 26 .

In the laser light source 1, when the pumping beams output from the pumping light sources 13, 14 are input into the optical amplification fibers 11, 12, each of the optical amplification fibers 11, 12 becomes pumped. This results in amplification of the light output by the first light source 17 of the seed light source in the light amplification fibers 11 , 12 and said amplified light is output from the laser source 1 . That is, the laser source 1 has a MOPA (Master Oscillator Power Amplifier) structure.

There is no particular limitation on the first light source 17 as long as it is a light source capable of outputting pulsed light of seed light; however, a YAG laser source or the like is suitably used. The first light source 17 in this embodiment outputs pulsed light (seed light) with a wavelength of 1064 nm at about 700 mW while supplying a driving current of about 200 mA. In the 1060nm wavelength band of the seed light, each optical amplification fiber 11, 12 has a gain.

The active medium used for optical amplification is preferably element Yb, which has a gain near the 1060nm wavelength compatible with existing YAG laser sources, and it is favorable in terms of power conversion efficiency because the wavelength of the pumping light is close to the one to be amplified wavelength of light. Therefore, the optical amplification fibers 11 and 12 are ideally YbDF (Yb-doped optical fiber) in which Yb is doped in the core. The optical amplification section in the laser source 1 is composed of a preamplifier section including an optical amplification fiber 11 and a booster amplifier section including an optical amplification fiber 12 .

The preamplifier part is composed of an optical amplifying fiber 11 , a pumping light source 13 and a combiner 15 for guiding the pumping light from the pumping light source 13 to the optical amplifying fiber 11 . The boost amplifier part is composed of an optical amplifying fiber 12 , a plurality of pumping light sources 14 and a combiner 16 for guiding the pumping light from the pumping light sources 14 to the optical amplifying fiber 12 .

In the preamplifier part, the optical amplification fiber 11 amplifies the seed light from the first light source 17 , and the seed light continuously transmits through the optical isolator 18 and the combiner 15 , and reaches the optical amplification fiber 11 . On the other hand, the pumping light output from the pumping light source 13 including the pumping LD module is supplied into the optical amplification fiber 11 through the combiner 15 in the forward direction. The pumping light has a wavelength of 975 nm and a power of the order of 5W. The optical amplification fiber 11 is phosphate-based YbDF, the core of which is doped with phosphorus (P) at a concentration of 26.4 wt% and aluminum (Al) at a concentration of 0.8 wt%, and the core is pumped. The optical amplification fiber 11 has a core diameter of 10 μm, a first cladding diameter of about 125 μm, an unsaturated absorption coefficient of 1.8 dB/m at a wavelength of 915 nm, and a length of 3.4 m. A bandpass filter 19 is located downstream of the optical amplification fiber 11 in order to suppress wavelengths other than the light output from the seed light source (first light source 17).

A multiplexer 23 is provided downstream of the bandpass filter 19 in the preamplifier section. The multiplexer 23 multiplexes the light output from the first light source 17 and amplified by the optical amplification fiber 11 with the light output from the second light source 21 . The multiplexed light obtained from multiplexing in the multiplexer 23 is output to the optical amplifying fiber 12 of the step-up amplifier section through the optical isolator 20 and the combiner 16 .

The second light source 21 is a light source that continuously outputs laser light with a wavelength of 1030 nm. Light output from the second light source 21 is controlled by the control unit 22 . The control unit 22 receives information such as seed light (pumping light) output start (OFF state→ON state) and suspension (ON state→OFF state) and the like from the first light source 17 through the line 170a, and controls the output from the first light source 17 according to the information. The second light source 21 outputs laser light (for example, CW light). A control method by the control unit 22 will be described in detail later.

In the boost amplifier section, the optical amplification fiber 12 amplifies the light that has passed through the combiner 16 . The pumping light beams provided from the respective pumping light sources 14 into the optical amplification fiber 12 through the combiner 16 in the forward direction have a wavelength of 975 nm and a power of 5W class. That is, the power of the pumping beam supplied to the optical amplification fiber 12 is 30W. Optical amplifying fiber 12 is Al co-doped silicon-based YbDF, the core of which is doped with aluminum (Al) at a concentration of 1.5 wt% and pumped. The optical amplifying fiber 12 has a core diameter of 10 μm, a first cladding diameter of about 125 μm, an unsaturated absorption coefficient of 1.5 dB/m at a wavelength of 915 nm, and a length of 4 m.

An end cap 24 is further arranged downstream of the optical amplification fiber 12 . The end cap 24 outputs the light amplified by the optical amplification fiber 12 . In addition, the lens 25 and the LWPF 26 are arranged downstream of the end cap 24. The light output from the end cap 24 is collimated by the lens 25, and then the collimated light is input into the LWPF 26. LWPF 26 is a long-wavelength transmission filter, and its light transmission is shown in Figure 2. When it is assumed that the wavelength (second wavelength) of light output from the second light source is shorter than the wavelength (first wavelength) of light output from the first light source, the light transmittance of the LWPF 26 is set so as to transmit light of the first wavelength light, and remove light of the second wavelength. Light that has passed through the LWPF 26 having such light transmittance is output as pulsed light from the laser light source 1. In order to remove only light of the second wavelength, a bandpass filter can be used in place of the LWPF 26 as a filter capable of passing only light of the first wavelength. However, in the case of outputting laser light at high power, there is a case where component light having a wavelength near 1100 nm is generated by nonlinear effects in the optical amplification fibers 11, 12 (for example, stimulated Raman scattering (SRS)) . Light of this long-wavelength component also contributes to laser processing. In the case where long-wavelength component light is to be utilized, it is preferable to use an LWPF capable of transmitting the long-wavelength component.

3A and 3B are views showing the multiplexer 23. As shown in FIG. 3A and 3B show the case where WDM is used as the multiplexer 23. As shown in FIG. In particular, as shown in FIG. 3A , the input ports of the light beams from the first light source 17 and from the second light source 21 are arranged at opposite positions with respect to the multiplexer 23 . Fig. 3B is a view showing the characteristics of a WDM filter. In FIG. 3B, curve S1 represents the transmittance of light at each wavelength of the WDM filter, and curve S2 represents the reflectance of light at each wavelength of the filter. As shown in FIG. 3B , light energy with a wavelength of 1064 nm output from the first light source 17 is transmitted by the multiplexer 23 and output to an output port. On the other hand, light with a wavelength of 1030 nm output from the second light source 21 is reflected in the WDM filter and output to the output port, and a small amount of light is transmitted to the input port of light from the first light source 17 . For this reason, as shown in FIG. 3A , although the first light source 17 and the second light source 21 are arranged to face each other with respect to the multiplexer 23, the light beams output from the first light source 17 and the second light source 21 can be in the same output in the direction. This structure allows the multiplexer 23 to multiplex the light output from the first light source 17 with the light output from the second light source 21 and output the multiplexed light to the optical isolator 20 . Instead of a WDM filter, the multiplexer 23 can also be a WDM coupler. The WDM coupler is a fused fiber coupler in which optical fibers are fused and spliced, and it is cheap and dense.

As shown in FIG. 1 , the irradiation direction of the laser light output from the laser source 1 is controlled by an electroscanner 100 or the like, which is arranged downstream of the end cap 24, and between the end cap 24 and the electroscanner Between 100 there is lens 25 and LWPF 26. The control unit 22 also receives operational information of the electroscanner 100 via the line 180a.

The output timing of the respective light beams from the first light source 17 and from the second light source 21 will be described below using FIGS. 4A , 4B, and 5 . 4A and 4B are views showing the output powers of the respective laser beams output from the laser source 1 . FIG. 5 is a view showing an example of processing a workpiece using the laser light source 1 .

As shown in FIG. 5 , this embodiment will describe a case where the surface of a workpiece P is processed using laser light output from a laser light source 1 . In particular, the surface of a flat plate-shaped workpiece P is processed in a plurality of linear regions (part A in FIG. 5 is a target region) in a direction parallel to the X-axis using laser light L output from a laser source 1 . The irradiation area of the laser source 1 moves over the area (part B in FIG. 5 ) connecting the ends of adjacent portions A located at the side edges of the workpiece P in the Y-axis direction. In this arrangement, the irradiated area of the laser light source 1 is alternately moved on the part A as the processing target and the part B as the unprocessed target, whereby it is possible to use the laser light L to treat a plurality of processing parts (parts) parallel to the X axis. A) to process. In this operation, it is necessary to suspend the irradiation with the laser light L while the irradiation area of the laser light source 1 is moved onto the portion B. As shown in FIG.

In order to process the workpiece P, as shown in FIG. 4A, the first light source 17 outputs pulsed light (ON state) with a wavelength of 1064 nm, and the laser source 1 outputs in the ON time band (time band shown by time _T11 in FIG. 4A ). From the pulsed laser light L1 amplified by the pulsed light, the irradiation area of the laser light output from the laser light source 1 in the ON time zone is located on the portion A in FIG. 5 . Next, the galvano scanner 100 suspends output of pulsed light from the first light source 17 during a period in which the irradiation area of the laser light from the laser light source 1 is located on part B in FIG. 5 (OFF state). This causes the output of the pulsed laser light L1 from the laser light source 1 to be suspended. However, during this pause period, the population inversion of the rare earth element added to the optical amplifying fiber 12 will rise to an extreme value, which will result in a point where irradiation with the pulsed laser light L1 from the laser source 1 is resumed ( The output power of the pulsed laser L1 at time T1 ( ₂ start point) has a temporary sharp increase, and the irradiation area of the laser light L from the laser source 1 comes to the part A in FIG. 5 again at the restart irradiation point; The above will result in a light surge. When a huge light surge is generated, it may cause malfunction, breakage, etc. in each part of the laser light source 1 .

In contrast, as shown in FIG. 4B , the laser light source 1 according to the present embodiment is configured to output light from the second light source 21 during an OFF time zone (a time zone indicated by time T2) in which The output of the seed light (pulse light) from the first light source 17 is suspended for a period not shorter than the pulse period of the pulse light (it is in an OFF state). Then, the light output from the second light source 21 is amplified by the optical amplification fiber 12 . The laser light L2 amplified by the optical amplifying fiber 12 is guided into the LWPF 26 through the end cap 24 and the lens 25 . Most of the laser light L2 output from the second light source 21 is blocked by the LWPF 26 . In a case where the laser light L2 is used during processing or the like or the laser light L2 is not harmful to the irradiation target, the filter like the LWPF 26 can be omitted. As described above, the light output from the second light source 21 is input into the optical amplifying fiber 12 during the OFF time zone to consume the pumping light input into the optical amplifying fiber 12, and this suppresses addition to the optical amplifying fiber 12. Significant increase in the number of rare earth element inversions. As a result, at the point at which the output of pulsed light from the first light source 17 is restarted (the start point of time _T12 ), it is possible to suppress generation of a huge light surge of the pulsed laser light L1.

After the output of the pulsed light from the first light source 17 is suspended, the output of light from the second light source 21 is preferably started without a time gap. In the case where there is a time gap between the pause time of outputting pulsed light from the first light source 17 and the start time of outputting light from the second light source 21 (that is, the case where there is a time zone in which no light is output from both light sources) , the population inversion of the rare earth element added in the optical amplifying fiber 12 will increase during the gap. In that case, a light surge may be generated once light output from the second light source 21 starts. To prevent this, it is preferable to start outputting light from the second light source 21 with a time gap equal to or less than the output period of the pulsed light output from the first light source 17 after suspending the output of the pulsed light from the first light source 17 . More specifically, in the case where the repetition frequency of the pulsed light output from the first light source 17 is 100 kHz, the time of one pulse period is 10 μs, and thus it is preferable to start from the first pulse within the time of one pulse period or during a pause. Within 10 μs after the light source 17 outputs the pulsed light, the laser light output from the second light source 21 starts.

It is also possible to adopt a mode in which the pumping state existence period of the rare earth element added in the optical amplifying fiber 12 is started from the second light source 50-200% earlier than the time point at which the first light source 17 enters the ON state. 21 to output laser light, that is, to start outputting laser light from the second light source 21 in a mode in which the rise time of the light output from the second light source 21 is set to 50%-200% of the pump state existence time of the rare earth element.

In the case of outputting laser light from the second light source 21, when the time required until the output intensity of the laser light reaches a fixed value (rise time) is too short, a light surge may be caused. When the rise time is too late, it will be difficult to satisfactorily suppress the rise of the population inversion of the rare earth element. For this reason, the rise time associated with the laser output from the second light source 21 (which is the time required to go from an intensity state of 10% of the desired output intensity to an intensity state of 90% of the desired output intensity) is preferably an approximate It is equal to 100 μs which is the pump state existence period of Yb ions to induce optical amplification action in the optical amplification fiber 12 . However, the rise time associated with outputting laser light from the second light source 21 may be set to 50-200% of the pumping state lifetime.

Control regarding the output of laser light from the first light source 17 and the second light source 21 is preferably performed in conjunction with the operation control of the galvano scanner 100 . For example, when the control unit 22 of the laser source 1 sends a control signal regarding the operation of the galvano scanner 100 to the galvano scanner 100 to scan the beam by controlling the irradiation position of the amplified laser light output from the laser source 1, the relevant Control signals for laser output from the first light source 17 and the second light source 21 are also sent to the laser light source 1 at the same time. More particularly, when the scanning direction of the laser light from laser source 1 is changed from X-axis direction (as the part A of processing target region) to Y-axis direction (as the part B of unprocessed region) in Fig. 5, with laser Output associated control signals are also sent to the control unit 22 to control the laser beam output from the first light source 17 and the second light source 21 , thereby being able to control the output of the laser beam from the first light source 17 and the second light source 21 . Another available method is a mode in which signals associated with the actuation (scanning state) and suspension of the motor of the galvano scanner to control the respective movements in the X-axis direction and the Y-axis direction are output to the outside , and wherein the suspension of the output of the laser beam from the first light source 17 and the second light source 21 is controlled in association with the actuation and suspension.

In order to perform laser processing on the workpiece P shown in FIG. The absence conditions (ON state and OFF state) can be linked eg based on FIG. 6 . In FIG. 6 , "1" indicates a scanning state of the galvano scanner 100 in the coherent direction, and "0" indicates a state in which the galvano scanner 100 stops scanning in the coherent direction. FIG. 6 also shows the case where both scans in the X-axis direction and the scans in the Y-axis direction are "0" and the cases where they are both "1". The reason for this is that the electroscanner 100 is composed of a solenoid motor or the like that reacts slowly to electrical signals, and the two conditions are provided for the states that occur due to the slow preparation conditions. That is, they represent the response to each light source in the case where the galvano scanner 100 causes transient relaxation oscillation during switching between scanning in the X-axis direction or in the Y-axis direction with an electric signal and stopping. control. In this case, for the purpose of avoiding light surge, it is preferable to set The first light source 17 and the second light source 21 are set in an ON state so that both light sources output laser light.

Contrary to the mode in which both the first light source 17 and the second light source 21 are switched between the ON state and the OFF state as shown in FIG. Two modes in which the light source 21 is switched between the ON state and the OFF state. FIG. 7 shows the relationship between the scanning direction of the galvano scanner and the laser beam outputs from the first light source 17 and the second light source 21 in this case.

As shown in FIG. 7, even in the case where the first light source 17 is always in the ON state, the peak of the pulsed light output from the laser light source 1 can be suppressed by using the second light source. In particular, in the case where the workpiece is composed of a material that is unlikely to be affected by heat, the relationship shown in FIG. It becomes easier to suppress the pulse peak of the pulsed light output from the laser source 1 when the irradiation position in the axial direction is scanned. The above embodiment has explained the case where the first light source 17 is in the ON state, but in case the pumping light is driven in the OFF state of the first light source for some reason, the effect of the present invention can be achieved by using The second light source becomes effective.

(second embodiment)

Next, a second embodiment of the laser light source according to the present invention will be described. FIG. 8 is a view showing the composition of a laser light source 2 according to the second embodiment. The laser source 2 differs from the laser source 1 in the following points. That is, the difference is that the laser light source 2 has a third light source 30 that outputs pulsed light at a wavelength different from that of the first light source 17 and the second light source 21 as seed light, and the pulsed beam output from the first light source 17 and the pulse beam output from the third light source The pulse beams output by 30 are multiplexed by multiplexer 31 , and then the multiplexed beams are input into optical isolator 18 and input into optical amplification fiber 11 through combiner 15 . Desirably, the wavelength of the second light source is different from the wavelength band including the respective wavelengths of the first light source and the third light source. A multiplexer 31 suitable here is the aforementioned WDM coupler.

In this manner, the seed light of the pulsed light output from the laser source 2 may be laser beams of various wavelength types. As in the first embodiment, the control unit 22 receives start (OFF state→ON state) and suspension (ON state→ OFF state), and control the output of laser light (for example, CW light) from the second light source 21 based on the information. The control unit 22 also receives operational information of the electroscanner 100 via the line 180b. Therefore, in the second embodiment, the light surge that occurs when the output of pulsed light beams from the first light source and the third light source is restarted can also be suppressed by outputting light from the second light source 21 during the OFF time zone, in which The output of pulsed light from the first light source and the third light source is suspended during the OFF time zone. Note here that various modified embodiments described in the first embodiment are also applicable to the second embodiment.

Various forms for preferred embodiments of the present invention have been described above, but the present invention is not limited to the above modes. For example, the above embodiment explained the mode using the optical amplifying fibers 11, 12 doped with Yb, but the optical amplifying fibers doped with Er may also be used instead of Yb. In this case, it is preferable to use a wavelength of 1550 nm for the pulsed light output from the first light source 17 and to use a wavelength of 1530 nm for the light output from the second light source 21 . However, when the intensity of the laser light output from the laser source 1 is high, it is preferable to use an optical amplification fiber doped with Yb so that the wavelength of the pumping light and the wavelength of the light to be amplified (seed light) are close to each other, as above mentioned.

It is preferable to determine the wavelength of the light output from the second light source 21 in the OFF state in which the output of the seed light from the first light source 17 is suspended to be close to two of the rare earth elements added in the optical amplifying fibers 11, 12 being one of Yb and Er. In this case the wavelength of the peak of the natural emission spectrum. In this case, it becomes more effective to suppress light surge by outputting light from the second light source 21 .

The above embodiments have described the form of using the optical amplifying fibers 11, 12 in the optical amplifier, but a mode in which a solid-state laser is used may also be used.

As described above, the present invention provides that in the state where the pumping light is supplied to the optical amplifier during the OFF state of the light source so as to maintain the thermal balance of the optical amplifier, no gigantic light occurs when changing from the OFF state of the light source to the ON state to output pulsed light. Surge laser source.

Claims (4)

1. lasing light emitter comprises:

First light source, the light that output has first wavelength is as pulsed light;

Secondary light source, output has the light of second wavelength that is different from first wavelength;

Optical amplifier is to amplifying from the light of first light source output and the light of exporting from secondary light source; With

Control unit is exported from the light of secondary light source according to the light output control from first light source,

Wherein said first light source have beginning and continue with the fixed cycle repeat to export the ON state of pulsed light and suspend at the duration that is no less than the said fixed cycle pulsed light output the OFF state and

Wherein, said control unit is given said optical amplifier at the duration control secondary light source output light that said first light source is in the OFF state.

2. lasing light emitter according to claim 1 also comprises filter, and it sees through the light with said first wavelength, but stops the light that from the amplification light of said optical amplifier output, has second wavelength.

3. lasing light emitter according to claim 1, wherein said control unit control secondary light source is ended light output at the state of first light source when OFF becomes ON or at the duration that first light source is in the ON state.

4. lasing light emitter according to claim 1, wherein said optical amplifier comprise be doped with optics amplify element as the optical fiber of optics amplifying medium and

Wherein be set to time of 50%-200% that said optics amplifies the pumping state life period of element from rise time of the light of secondary light source output.

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