JP5557601B2 - Laser light source adjustment system - Google Patents

Description

  The present invention relates to a laser light source and a laser light source adjustment system.

  Conventionally, a light source, a resonator that oscillates the fundamental wave light in multimode using the light emitted from the light source as excitation light, and an optical axis inside the resonator are arranged to convert the fundamental wave light into light of a predetermined wavelength. A non-linear optical crystal, an etalon disposed on the optical axis inside the resonator and transmitting light of a predetermined wavelength to make light emitted from the resonator into a single mode, and an optical path of the resonator There is known a laser light source that is disposed in a subsequent stage and includes an iodine cell that detects a saturated absorption line of iodine, and stabilizes the center wavelength of light emitted from the resonator based on the saturated absorption line of iodine. (For example, refer to Patent Document 1).

  A frequency-stabilized laser (laser light source) described in Patent Document 1 includes an excitation semiconductor laser (light source), a resonant wave generation unit (resonator), a KTP crystal (nonlinear optical crystal), two etalons, iodine And a cell. Further, in the frequency stabilized laser disclosed in Patent Document 1, the resonance of the resonant wave generator is adjusted by adjusting the angle of each etalon with respect to the optical axis of the resonant wave generator, the temperature of the resonant wave generator, and the resonator length in the resonant wave generator. The light emitted from the wave generator is set to a single mode, and the wavelength and intensity of the light emitted from the resonant wave generator are adjusted (hereinafter, adjusting the wavelength and intensity of the light is simply To adjust the light).

Here, when the angle of the etalon with respect to the optical axis of the resonator is adjusted, the wavelength transmission characteristic of the etalon can be changed. In addition, adjusting the angle of the etalon with respect to the optical axis of the resonator changes the optical path length of the etalon, which in turn changes the resonator length in the resonator, thus changing the mode interval of light oscillating in multimode. .
When the temperature of the resonator is adjusted, the temperature of the etalon changes, so that the wavelength transmission characteristics of the etalon can be changed. Further, when the temperature of the resonator is adjusted, the resonator length in the resonator changes due to the effects of thermal expansion and contraction, so that the mode interval of light oscillating in multimode also changes.
Furthermore, when the resonator length in the resonator is adjusted, the mode interval of light oscillating in multimode can be changed.

  In the frequency-stabilized laser described in Patent Document 1, first, the light emitted from the resonator is converted into a single light by adjusting the angle of each etalon with respect to the optical axis of the resonant wave generator and the temperature of the resonant wave generator. It is adjusted to have the maximum intensity in the mode. Then, by adjusting the resonator length in the resonance wave generator, the mode interval of the light oscillating in the multimode is changed so that the wavelength of the light emitted from the resonator becomes the target wavelength.

JP 2007-19361 A

  However, in the frequency stabilized laser disclosed in Patent Document 1, the angle of each etalon with respect to the optical axis of the resonance wave generation unit, the temperature of the resonance wave generation unit, and the resonator length in the resonance wave generation unit are determined from the resonance wave generation unit. Since it is fixed in the state when the emitted light is adjusted, for example, it is emitted from the frequency stabilized laser due to the influence of the temperature change of the environment where the frequency stabilized laser is used, the secular change of the frequency stabilized laser, etc. There is a problem that the wavelength and intensity of the emitted light may change.

An object of the present invention is to provide temperature characteristics, and long-term stability can be improved Relais chromatography The source of the adjustment system.

  The laser light source adjustment system of the present invention is disposed on a light source, a resonator that oscillates fundamental wave light in multimode using light emitted from the light source as excitation light, and an optical axis inside the resonator, A nonlinear optical crystal for converting the fundamental wave light into light of a predetermined wavelength, and an optical axis inside the resonator, are emitted from the resonator by transmitting light of a predetermined wavelength. An etalon that converts light into a single mode and an iodine cell that is disposed downstream of the optical path of the resonator and detects a saturated absorption line of iodine, and is emitted from the resonator based on the saturated absorption line of iodine. A laser light source adjustment system that stabilizes the center wavelength of the light to be detected, the spectrum detecting means for detecting the spectrum of the light emitted from the resonator, and the wave for detecting the wavelength of the light emitted from the resonator A detection means; and an adjustment control means for controlling the laser light source and the adjustment system, wherein the adjustment control means is detected by the spectrum detection means with the etalon removed from the resonator. A temperature adjustment unit for adjusting a temperature parameter of the nonlinear optical crystal so that a peak wavelength of the spectrum and a wavelength of the saturated absorption line of iodine coincide with each other, and the wavelength in a state where the etalon is attached to the resonator. At least one of the angle of the etalon with respect to the optical axis of the resonator and the temperature of the etalon so that the wavelength detected by the detection means matches the wavelength of the saturated absorption line of iodine, and the resonator And a resonator adjustment unit that adjusts each parameter with the resonator length.

  According to such a configuration, the laser light source adjustment system includes the adjustment control unit, and the adjustment control unit includes the temperature adjustment unit. Therefore, the light that adjusts the temperature of the nonlinear optical crystal and oscillates in a multimode. By changing the spectrum, the light emitted from the resonator can be adjusted so that the peak wavelength of the spectrum detected by the spectrum detector matches the wavelength of the saturated absorption line of iodine.
  Note that the peak wavelength of the spectrum refers to the wavelength that is the maximum value of the spectrum, and when there are multiple peak wavelengths of the spectrum, the temperature adjustment unit determines the maximum peak wavelength and the wavelength of the saturated absorption line of iodine. It is preferable that the light emitted from the resonator is adjusted so as to coincide with each other.

  In addition, since the adjustment control means includes the resonator adjustment unit, the mode interval of the light oscillated in the multimode based on adjusting at least one of the angle of the etalon with respect to the optical axis of the resonator and the temperature of the etalon. The change can be canceled by adjusting the resonator length in the resonator. Therefore, the resonator adjustment unit can adjust each parameter without changing the wavelength of the light emitted from the resonator, and can adjust the light emitted from the resonator with high accuracy and appropriateness.

  In the present invention, the laser light source includes intensity detection means for detecting the intensity of light emitted from the resonator, and light source control means for controlling the laser light source, and the light source control means includes the intensity detection. A light source control unit for controlling a current for driving the light source so as to make the intensity of light detected by the means constant, a temperature for the nonlinear optical crystal so as to reduce a current for driving the light source, It is preferable to include a current adjusting unit that adjusts parameters of at least one of the angle of the etalon with respect to the optical axis of the resonator and the temperature of the etalon, and the resonator length in the resonator.

  According to such a configuration, since the laser light source includes the light source control unit and the light source control unit includes the light source control unit, a change in temperature of the environment in which the laser light source is used, a secular change of the laser light source, and the like It is possible to suppress the intensity of light emitted from the laser light source from changing due to the influence of the above.
  Further, since the light source control means includes the current adjusting unit, the current for driving the light source can be reduced. Therefore, power consumption of the light source can be suppressed, and the life of the light source can be extended.

  Here, since the center wavelength of the light emitted from the resonator is stabilized based on the saturated absorption line of iodine, the current adjustment unit does not change the wavelength of the light emitted from the resonator. Each parameter can be adjusted. That is, according to the present invention, the temperature characteristics and long-term stability of the laser light source can be improved.
  Note that when the temperature of the nonlinear optical crystal is adjusted, the spectrum of light oscillating in a multimode changes. In addition, the change in the spectrum of light oscillating in multimode based on adjusting the temperature of the nonlinear optical crystal is due to the change in the mode interval of light oscillating in multimode based on adjusting the resonator length in the resonator. Is also big. Therefore, the laser light source can be adjusted efficiently.

  In the present invention, the current adjustment unit adjusts each parameter so that a current for driving the light source becomes a minimum value, and the light source control means determines that the minimum value exceeds a predetermined current value. It is preferable to provide an abnormality determination unit that determines that the laser light source is abnormal.

  According to such a configuration, the abnormality determination unit determines that the laser light source is abnormal when the minimum value of the current that drives the light source adjusted by the current adjustment unit exceeds a predetermined current value. The user can determine the lifetime of the laser light source based on the determination by the abnormality determination unit.
  According to the present invention, since the current adjustment unit adjusts each parameter so that the current for driving the light source becomes the minimum value, the power consumption of the light source can be further suppressed, and the lifetime of the light source can be further increased. Can be long.

  In the present invention, the light source control means adjusts the parameters by reading information stored in the storage unit and a storage unit that stores information on the parameters adjusted by the current adjustment unit. And a read adjustment unit for adjusting light emitted from the resonator.

  According to such a configuration, the light source control means includes the storage unit and the read adjustment unit. For example, when each parameter is adjusted by the current adjustment unit, information related to each parameter is stored in the storage unit. In addition, the light source control means can be configured to cause the reading adjustment unit to adjust each parameter when the laser light source is activated. According to this, the light emitted from the resonator when the laser light source is activated can be quickly adjusted, and can be adjusted accurately and appropriately.

The schematic diagram which shows the laser light source which concerns on one Embodiment of this invention. The schematic diagram which shows the detailed structure of the control means for light sources which concerns on one Embodiment of this invention. The schematic diagram which shows the adjustment system of the laser light source which concerns on one Embodiment of this invention. The flowchart which shows the adjustment process of the laser light source which concerns on one Embodiment of this invention. The graph which shows the spectrum of the light radiate | emitted from the laser light source which concerns on one Embodiment of this invention, and the wavelength transmission characteristic of an etalon.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Schematic configuration of laser light source]
FIG. 1 is a schematic diagram showing a laser light source 1 according to an embodiment of the present invention. In FIG. 1, the optical axis of the laser light source 1 is indicated by a one-dot chain line.
As shown in FIG. 1, the laser light source 1 includes a light source 2 that emits light, a resonator 3 that oscillates fundamental light in multimode using light emitted from the light source 2 as excitation light, and a light emitted from the resonator 3. Light guide means 4 for guiding the light to the outside of the laser light source 1, saturated absorption line detection means 5 for detecting saturated absorption lines of iodine by modulating the light emitted from the resonator 3, and a laser And a light source control means 6 for controlling the light source 1.
The light source 2 includes a semiconductor laser 21 that emits light (excitation light) having a wavelength near 808 nm, and a parallelizing lens 22 that collimates the excitation light emitted from the semiconductor laser 21.

The resonator 3 includes a housing 31, and a condensing lens 32 that condenses the excitation light collimated by the parallelizing lens 22 and a condensing lens 32 are condensed inside the housing 31. Nd: YVO ₄ crystal 33 that emits light having a wavelength of around 1064 nm (fundamental wave light) and an optical axis inside resonator 3 and is emitted from Nd: YVO ₄ crystal 33. KTP crystal 34 as a nonlinear optical crystal for converting the fundamental wave light to light having a wavelength of around 532 nm (hereinafter referred to as second harmonic light), and an etalon 35 disposed downstream of the optical path of KTP crystal 34, And a resonator mirror 36, a housing 31, and a piezo element 37 disposed between the resonator mirror 36.

The surface of the Nd: YVO ₄ crystal 33 on the side of the semiconductor laser 21 is coated with a coating for transmitting the excitation light and reflecting the fundamental light. The surface of the resonator mirror 36 on the side of the Nd: YVO ₄ crystal 33 is The coating for reflecting the fundamental wave light and transmitting the second harmonic light is applied. Therefore, the fundamental wave light reciprocates between the Nd: YVO ₄ crystal 33 and the resonator mirror 36 and oscillates in multimode, and the second harmonic light passes through the resonator mirror 36 and is emitted from the resonator 3. The

The etalon 35 is disposed on the optical axis inside the resonator 3 and transmits light of a predetermined wavelength, and the fundamental light oscillated in a multimode can be changed to a single mode. Note that by setting the fundamental wave light to the single mode, the second harmonic light converted by the KTP crystal 34 can also be set to the single mode.
The piezo element 37 is an element that is deformed by applying a voltage. Under the control of the light source control means 6, the distance between the Nd: YVO ₄ crystal 33 and the resonator mirror 36, that is, resonance in the resonator 3. Adjust the instrument length.

The light guide means 4 includes filters 41 and 42 disposed downstream of the optical path of the resonator 3, a half-wave plate 43 that adjusts the polarization direction of light transmitted through the filters 41 and 42, and a half-wave plate And a polarization beam splitter 44 for separating the light whose polarization direction is adjusted at 43.
The filter 41 has a function of attenuating excitation light that is leakage light from the resonator 3. The filter 42 is disposed in an inclined state with respect to the optical axis of the laser light source 1 and has a function of reflecting the fundamental wave light that is leaked from the resonator 3. The light is guided in a direction away from the optical axis of the laser light source 1. That is, the second harmonic light that passes through the filters 41 and 42 is incident on the half-wave plate 43.
The polarization beam splitter 44 has a polarization separation film 44A. Of the light emitted from the half-wave plate 43 and incident on the polarization beam splitter 44, the P-polarized light passes through the polarization separation film 44A and the S-polarized light passes through the polarization separation film 44A. Reflects the polarization separation film 44A.

The light guide 4 includes a beam splitter 45 for separating the S-polarized light reflected by the polarization beam splitter 44, and an intensity detector for detecting the intensity of the light separated by the beam splitter 45. 46.
The beam splitter 45 reflects a part of incident light at the interface 45A and transmits the other part.

Next, the optical path in the light guide 4 will be described.
The S-polarized light reflected by the polarization beam splitter 44 enters the beam splitter 45. Of the light that has entered the beam splitter 45, the light that has passed through the beam splitter 45 enters the intensity detector 46. The intensity detection unit 46 detects the intensity of the incident light and outputs a signal based on the detected light intensity to the light source control means 6. That is, the intensity detector 46 functions as an intensity detector that detects the intensity of the light emitted from the resonator 3. The light reflected by the beam splitter 45 is emitted to the outside of the laser light source 1.

The saturated absorption line detection means 5 includes a polarization beam splitter 51 that makes P-polarized light transmitted through the polarization beam splitter 44 incident, a quarter-wave plate 52 that makes light transmitted through the polarization beam splitter 51 incident, and 1/4. The iodine cell 53 disposed downstream of the optical path of the wave plate 52, that is, the downstream of the optical path of the resonator 3, the reflection mirror 54 reflecting the light transmitted through the iodine cell 53, and the light reflected by the polarization beam splitter 51 And an intensity detector 55 for detecting the intensity.
The polarization beam splitter 51 has a polarization separation film 51 </ b> A and has the same function as the polarization beam splitter 44. The quarter-wave plate 52 has a function of providing a 90 ° phase difference between orthogonal deflection components of incident light.

Next, the optical path in the saturated absorption line detection means 5 will be described.
The P-polarized light that has passed through the polarization beam splitter 44 passes through the polarization beam splitter 51 and enters the iodine cell 53 via the quarter-wave plate 52. The light transmitted through the iodine cell 53 is reflected by the reflection mirror 54, passes through the iodine cell 53 and the quarter wavelength plate 52, and enters the polarization beam splitter 51 again. At this time, since the light incident on the polarization beam splitter 51 has passed through the quarter-wave plate 52 twice, the polarization direction is rotated by 90 degrees and becomes S-polarized light with respect to the polarization separation film 51A. . Therefore, the light that has entered the polarization beam splitter 51 again is reflected by the polarization separation film 51A. The light reflected by the polarization beam splitter 51 enters the intensity detector 55. The intensity detection unit 55 detects the intensity of the incident light and outputs a signal based on the detected light intensity to the light source control means 6.

  The light source control means 6 is composed of a CPU (Central Processing Unit), a memory, etc., controls the intensity detectors 46, 55, the semiconductor laser 21, the KTP crystal 34, the piezo element 37, the resonator 3, and the iodine cell. 53 is controlled. The light source control means 6 modulates the light emitted from the resonator 3 by applying a voltage to the piezo element 37 to control the resonator length in the resonator 3. The light source controller 6 stabilizes the center wavelength of the light emitted from the resonator 3 by detecting the saturated absorption line of iodine based on the signal output from the intensity detector 55.

FIG. 2 is a schematic diagram showing a detailed configuration of the light source control means 6.
As shown in FIG. 2, the light source control means 6 includes a storage unit 61, a light source control unit 62, a current adjustment unit 63, an abnormality determination unit 64, and a read adjustment unit 65.
The storage unit 61 stores information used by the light source control means 6.
Based on the signal output from the intensity detector 46, the light source controller 62 controls the current that drives the semiconductor laser 21 so that the intensity of light incident on the intensity detector 46 is constant.

  The current adjustment unit 63 adjusts each parameter of the temperature of the KTP crystal 34 and the resonator length in the resonator 3 so that the current for driving the semiconductor laser 21 becomes the minimum value. The semiconductor laser 21, the KTP crystal 34, the resonator 3, and the iodine cell 53 are attached with a thermistor for detecting the temperature and a temperature regulator composed of a Peltier element for adjusting the temperature. Yes. The current adjusting unit 63 adjusts the temperature of the KTP crystal 34 by controlling the temperature adjuster. Information relating to each parameter adjusted by the current adjustment unit 63 is stored in the storage unit 61.

The abnormality determination unit 64 determines that the laser light source 1 is abnormal when the minimum value of the current for driving the semiconductor laser 21 adjusted by the current adjustment unit 63 exceeds a predetermined current value.
The read adjustment unit 65 adjusts each parameter by reading the information stored in the storage unit 61 and adjusts the light emitted from the resonator 3. The read adjustment unit 65 adjusts each parameter when the laser light source 1 is activated.

[Laser light source adjustment system]
FIG. 3 is a schematic diagram showing an adjustment system 10 for the laser light source 1.
As shown in FIG. 3, the adjustment system 10 of the laser light source 1 has a beam splitter 11 for separating the light reflected by the beam splitter 45, and the spectrum and wavelength of the light separated by the beam splitter 11. Detection means 12 for detection, laser light source 1, and adjustment control means 13 for controlling detection means 12 are provided.

The beam splitter 11 reflects a part of incident light at the interface 11A and transmits the other part. Of the light incident on the beam splitter 11, the light reflected by the beam splitter 11 enters the detection means 12. The detection unit 12 detects the spectrum and wavelength of the incident light, and outputs a signal based on the detected spectrum and wavelength of the light to the adjustment control unit 13. Further, the light transmitted through the beam splitter 11 is emitted to the outside of the laser light source 1.
The detection means 12 includes an optical spectrum analyzer 121 as a spectrum detection means for measuring the spectrum of light, and an optical wavelength meter 122 as a wavelength detection means for measuring the wavelength of light.

  The adjustment control means 13 includes a CPU, a memory, and the like, and includes a temperature adjustment unit 131 and a resonator adjustment unit 132. The light source control means 6 and the adjustment control means 13 are connected so as to be able to transmit / receive information to / from each other. The adjustment control unit 13 can indirectly control the temperature of the KTP crystal 34, the temperature of the etalon 35, the resonator length in the resonator 3, and the like via the light source control unit 6. Note that the temperature of the etalon 35 can be adjusted by adjusting the temperature of the resonator 3.

The temperature adjustment unit 131 adjusts the KTP crystal 34 so that the peak wavelength of the spectrum detected by the optical spectrum analyzer 121 with the etalon 35 removed from the resonator 3 matches the wavelength of the saturated absorption line of iodine. Adjust the temperature parameter.
The resonator adjustment unit 132 is a saturated absorption line of iodine detected based on the wavelength detected by the optical wavelength meter 122 with the etalon 35 attached to the resonator 3 and the signal output from the intensity detection unit 55. The parameters of the temperature of the etalon 35 and the resonator length in the resonator 3 are adjusted so as to match the wavelengths of the etalon 35.

[Laser light source adjustment processing]
FIG. 4 is a flowchart showing the adjustment process of the laser light source 1. FIG. 5 is a graph showing the spectrum S of the light emitted from the laser light source 1 and the wavelength transmission characteristic W of the etalon 35. In FIG. 5, the vertical axis represents the intensity of the spectrum S and the transmittance of the etalon 35, and the horizontal axis represents the wavelength.
When the adjustment process of the laser light source 1 is executed, as shown in FIG. 4, the adjustment control means 13 executes the following steps S1 to S3.

  Specifically, the temperature adjustment unit 131 adjusts the temperature parameter of the KTP crystal 34 with the etalon 35 removed from the resonator 3, and the optical spectrum analyzer 121 adjusts the temperature parameter of the KTP crystal 34 as indicated by an arrow in FIG. The peak wavelength of the detected spectrum S is matched with the wavelength of the saturated absorption line of iodine (S1: temperature adjustment step). In FIG. 5, the wavelength of the saturated absorption line of iodine is 532.245 nm.

When the temperature parameter of the KTP crystal 34 is adjusted in the temperature adjustment step S <b> 1, the resonator adjustment unit 132 sets the temperature of the etalon 35 and the resonator length in the resonator 3 with the etalon 35 attached to the resonator 3. And the wavelength detected by the optical wavelength meter 122 and the wavelength of the saturated absorption line of iodine detected based on the signal output from the intensity detector 55 are matched (S2: resonance) Adjustment step).
Here, the resonator adjustment unit 132 can change the wavelength transmission characteristic W of the etalon 35 by adjusting the temperature of the etalon 35 as indicated by an arrow in FIG.

In addition, the resonator adjustment unit 132 can cancel the change in the mode interval of the light oscillated in the multimode based on the adjustment of the temperature of the etalon 35 by adjusting the resonator length in the resonator 3.
Therefore, the resonator adjustment unit 132 can adjust each parameter without changing the wavelength of the light emitted from the resonator 3, and is detected by the optical spectrum analyzer 121 as shown in FIG. The peak wavelength of the spectrum S to be detected, the wavelength detected by the optical wavelength meter 122, that is, the wavelength transmitted through the etalon 35, and the saturated absorption line of iodine detected based on the signal output from the intensity detector 55 The wavelength can be matched.

When the parameters of the temperature of the etalon 35 and the resonator length in the resonator 3 are adjusted in the resonator adjustment step S <b> 2, the adjustment control unit 13 uses the temperature adjustment unit 131 and the resonator adjustment unit 132. Information relating to each adjusted parameter is stored in the storage unit 61 (S3: storage step).
By executing the above steps S1 to S3, the adjustment control means 13 executes the adjustment process.

According to this embodiment, there are the following effects.
(1) Since the laser light source 1 includes the light source control unit 6 and the light source control unit 6 includes the light source control unit 62, a change in the temperature of the environment in which the laser light source 1 is used and a secular change of the laser light source 1 are included. It is possible to suppress the intensity of light emitted from the laser light source 1 from being changed due to the influence of the above. Further, since the light source control means 6 includes the current adjusting unit 63, the current for driving the semiconductor laser 21 can be reduced. Therefore, the power consumption of the semiconductor laser 21 can be suppressed, and the life of the semiconductor laser 21 can be extended. Here, since the center wavelength of the light emitted from the resonator 3 is stabilized based on the saturated absorption line of iodine, the current adjusting unit 63 changes the wavelength of the light emitted from the resonator 3. It is possible to adjust each parameter without making it. Therefore, the temperature characteristics and long-term stability of the laser light source 1 can be improved.

(2) The abnormality determination unit 64 determines that the laser light source 1 is abnormal when the minimum value of the current for driving the semiconductor laser 21 adjusted by the current adjustment unit 63 exceeds a predetermined current value. Can determine the life of the laser light source 1 based on the determination by the abnormality determination unit 64.
(3) Since the current adjustment unit 63 adjusts each parameter so that the current for driving the semiconductor laser 21 becomes the minimum value, the power consumption of the semiconductor laser 21 can be further suppressed, and the lifetime of the semiconductor laser 21 can be suppressed. Can be further increased.
(4) Since the light source control means 6 includes the storage unit 61 and the read adjustment unit 65, the light emitted from the resonator 3 can be quickly adjusted when the laser light source 1 is activated, High precision and appropriate adjustment can be made.

(5) Since the adjustment system 10 of the laser light source 1 includes the adjustment control unit 13 and the adjustment control unit 13 includes the temperature adjustment unit 131, the light that oscillates in a multimode by adjusting the temperature of the KTP crystal 34. The light emitted from the resonator 3 can be adjusted so that the peak wavelength of the spectrum S detected by the optical spectrum analyzer 121 matches the wavelength of the saturated absorption line of iodine. it can. In addition, since the adjustment control means 13 includes the resonator adjustment unit 132, the change in the mode interval of the light oscillated in the multimode based on the adjustment of the temperature of the etalon 35 is adjusted, and the resonator length in the resonator 3 is adjusted. This can be offset. Therefore, the resonator adjustment unit 132 can adjust each parameter without changing the wavelength of the light emitted from the resonator 3, and can accurately adjust the light emitted from the resonator with high accuracy. it can.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the current adjustment unit 63 adjusts the parameters of the temperature of the KTP crystal 34 and the resonator length in the resonator 3 so that the current for driving the semiconductor laser 21 becomes the minimum value. However, it is not necessary to adjust so as to be the minimum value. In short, the current adjustment unit may adjust each parameter so that the current for driving the light source becomes small.

In the above embodiment, the current adjusting unit 63 adjusts the parameters of the temperature of the KTP crystal 34 and the resonator length in the resonator 3, but the angle of the etalon 35 with respect to the optical axis of the resonator 3 or the etalon Each parameter of the temperature of 35 and the resonator length in the resonator 3 may be adjusted. In short, the current adjusting unit may adjust each parameter of at least one of the temperature of the nonlinear optical crystal, the angle of the etalon with respect to the optical axis of the resonator, and the temperature of the etalon, and the resonator length in the resonator.
In the embodiment, the light source control means 6 includes the storage unit 61, the abnormality determination unit 64, and the read adjustment unit 65, but may not include these functions.

  In the above embodiment, the resonator adjustment unit 132 adjusts the parameters of the temperature of the etalon 35 and the resonator length in the resonator 3, but the angle of the etalon 35 with respect to the optical axis of the resonator 3 and the resonance Each parameter of the resonator length in the resonator 3 may be adjusted. In short, the resonator adjustment unit may adjust each parameter of at least one of the angle of the etalon with respect to the optical axis of the resonator, the temperature of the etalon, and the resonator length in the resonator.

In the embodiment, the temperature adjustment unit 131 and the resonator adjustment unit 132 adjust the temperature of the etalon 35 by adjusting the temperature of the resonator 3. However, the temperature adjustment unit 131 and the resonator adjustment unit 132 directly adjust the temperature of the etalon 35. May be.
In the above-described embodiment, the optical wavelength meter 122 is used as the wavelength detecting means. However, the light wavelength meter 122 is emitted from the resonator 3 based on the saturated absorption line of iodine detected based on the signal output from the intensity detector 55. The wavelength detecting means may be configured by detecting the wavelength of the light to be detected.

  The present invention can be suitably used for a laser light source and a laser light source adjustment system.

DESCRIPTION OF SYMBOLS 1 ... Laser light source 2 ... Light source 3 ... Resonator 6 ... Light source control means 10 ... Adjustment system 13 ... Adjustment control means 21 ... Semiconductor laser (light source)
34 ... KTP crystal (nonlinear optical crystal)
35 ... Etalon 46 ... Intensity detector (intensity detector)
53 ... Iodine cell 61 ... Storage unit 62 ... Light source control unit 63 ... Current adjustment unit 64 ... Abnormality determination unit 65 ... Reading adjustment unit 121 ... Optical spectrum analyzer (spectrum detection means)
122: Optical wavelength meter (wavelength detection means)
131 ... Temperature adjustment unit 132 ... Resonator adjustment unit

Claims (4)

  A light source, a resonator that oscillates fundamental wave light in multimode using light emitted from the light source as excitation light, and an optical axis inside the resonator, the fundamental wave light having a predetermined wavelength; A non-linear optical crystal for conversion, an etalon disposed on an optical axis inside the resonator, and transmitting light of a predetermined wavelength to make light emitted from the resonator into a single mode; A laser disposed in the latter stage of the optical path of the resonator, comprising an iodine cell for detecting a saturated absorption line of iodine, and stabilizing a central wavelength of light emitted from the resonator based on the saturated absorption line of iodine A light source adjustment system,
  Spectrum detecting means for detecting the spectrum of light emitted from the resonator;
  Wavelength detecting means for detecting the wavelength of light emitted from the resonator;
  An adjustment control means for controlling the laser light source and the adjustment system;
  The adjustment control means includes
  The temperature parameter of the nonlinear optical crystal is set so that the peak wavelength of the spectrum detected by the spectrum detection means in a state in which the etalon is removed from the resonator matches the wavelength of the saturated absorption line of iodine. A temperature adjustment unit to be adjusted;
  The angle of the etalon with respect to the optical axis of the resonator so as to match the wavelength detected by the wavelength detection means with the etalon attached to the resonator, and the wavelength of the saturated absorption line of iodine, And a resonator adjustment unit for adjusting parameters of at least one of the temperatures of the etalon and a resonator length of the resonator. In the adjustment system of the laser light source of Claim 1,
The laser light source is
Intensity detecting means for detecting the intensity of light emitted from the resonator;
A light source control means for controlling the laser light source,
The light source control means includes:
A light source control unit that controls a current for driving the light source so that the intensity of light detected by the intensity detection unit is constant;
At least one of the temperature of the nonlinear optical crystal, the angle of the etalon with respect to the optical axis of the resonator, and the temperature of the etalon, and the resonator length in the resonator, so as to reduce the current that drives the light source An adjustment system for a laser light source , comprising: a current adjustment unit for adjusting each parameter. In the adjustment system of the laser light source of Claim 2 ,
The current adjusting unit is
Adjust each parameter so that the current for driving the light source becomes a minimum value,
The light source control means includes:
An adjustment system for a laser light source, comprising: an abnormality determination unit that determines that the laser light source is abnormal when the minimum value exceeds a predetermined current value. In the adjustment system of the laser light source of Claim 2 or Claim 3 ,
The light source control means includes:
A storage unit for storing information on each parameter adjusted by the current adjustment unit;
A laser light source adjustment system comprising: a read adjustment unit that adjusts each parameter by reading information stored in the storage unit and adjusts light emitted from the resonator.

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