CN1482437A - Apparatus and method for detecting semiconductor laser and coherent optical source detecting process - Google Patents

Abstract

The invention provides the linking process and apparatus of the optical fiber amplifier supporting single fiber two way optical transmission characterized by that, the checkout gear comprises an power supply, an optical receiving element 3 and transmission type wave length selection elements. In the state when the transmission type wave length selection element 6 is inserted, on the optical path from the wave length variable DBR semiconductor laser 1 to the optical receiving element 3, varying at least one party of the phase current provided to the phase adjustment area and the DBR current provided by the DBR area, using optical receiving element 3 to detect the laser light output strength after the transmission type wave length selection element 6 is inserted.

Description

The pick-up unit of semiconductor laser and method and coherent source detection method

[detailed description of the invention]

[technical field that the present invention belongs to]

The present invention relates to have the Wavelength variable function, be used for the pick-up unit of wavelength variable semiconductor laser of optical communication field and 2 subharmonic generations etc. and the detection method of detection method and coherent source.

[prior art]

In recent years, the semiconductor laser with Wavelength variable function just attracts much attention in the application of optical communication field etc. and the first-harmonic that takes place as 2 subharmonic that utilize nonlinear effect.Distributed feed-back type (DFB) semiconductor laser of integrated grating and Bragg reflective type (DBR) semiconductor laser are that available single laser instrument obtains single longitudinal mode and swashs the semiconductor laser of penetrating on semiconductor laser.Now, the dbr semiconductor laser instrument is realizing having become vitals aspect long distance, the high capacity optical communication system with the dfb semiconductor laser instrument.

As the Wavelength variable mode, proposed the DBR portion supplying electric current on the dbr semiconductor laser instrument, by means of producing the method that variations in refractive index is come tuning excitation wavelength by plasma effect and temperature variation.

Below the dbr semiconductor laser instrument with Wavelength variable function is described (people such as Hengshan Mountain: the electric paper will C of association, Vol.120-C, P398 put down into 12 years).The AlGaAs that figure 14 illustrates 3 electrode structures is the schematic configuration of Wavelength variable dbr semiconductor laser instrument.

As shown in figure 14, Wavelength variable dbr semiconductor laser instrument 34 has active area 35, phase place adjustment district 36 and 37 these 3 zones, DBR district.Method for making to Wavelength variable dbr semiconductor laser instrument 34 with this structure is illustrated simply below.At first, behind epitaxial growth n type AlGaAs on the n type GaAs substrate, form the AlGaAs active area with the MOCVD device.As interlayer, stacked p type AlGaAs forms the optical waveguide of ridge structure again with photoetching technique.Then on optical waveguide, form 1 grating (cycle 100nm) with electron beam scanning.DBR district and the phase place adjustment district that has formed grating carried out the injection of Si ion, form passive optical waveguide.Follow again, carry out the 2nd crystal growth, as interlayer, stacked p type AlGaAs, last, the electrode of electric current is provided providing in n side and p side.

The AlGaAs of 3 electrode structures is that the threshold value of Wavelength variable dbr semiconductor laser instrument is 25mA, for the electric current (working current) of the 150mA that supplies with to active area, can obtain the output power of 50mW.Figure 15 illustrates the Wavelength variable characteristic when the DBR district carried out current supply.Supplying electric current (dbr current) by means of changing the DBR district makes the refractive index in DBR district change because of heating, can realize Wavelength variable.The semiconductor laser that penetrates is directed to spectroanalysis instrument, has observed excitation wavelength.Working current 100mA, phase current 0mA have been obtained the wavelength variable width of stair-stepping 2nm shown in Figure 15.Excitation wavelength also remains single longitudinal mode when Wavelength variable.

Secondly, phase current is set at 20mA, similarly measures the Wavelength variable characteristic when dbr current is changed.Then, again phase current is set at 40mA, similarly measures the Wavelength variable characteristic when dbr current is changed.According to the gained result, figure 16 illustrates mapping result to the dbr current value (constituting the current value A point of the step of ladder) that mode hopping takes place.As known in the figure,, make the relation of its holding current, can realize wavelength continuous variable characteristic shown in Figure 17 than Idbr/Iph=0.5 by means of controlling dbr current (Idbr) and phase current (Iph) simultaneously.

[inventing problem to be solved]

As mentioned above, in Wavelength variable dbr semiconductor laser instrument and dfb semiconductor laser instrument, its Wavelength variable characteristic is very important.Key factor as the Wavelength variable characteristic is (i) single longitudinal mode characteristic, (ii) wavelength variable reappearance, the (iii) necessary current ratio Idbr/Iph of wavelength continuous variable.The single longitudinal mode characteristic is the characteristic that at first requires in optical communication purposes and the generation of 2 subharmonic, in a single day becomes multimode at aspect longitudinal modes such as 2 subharmonic generations, can cause conversion efficiency to reduce significantly.Wavelength variable reappearance is the key property of wavelength control aspect, at first is that dullness shown in Figure 15 increases characteristic, and in addition, the good reproduction of Wavelength variable characteristic is very important.As for the necessary current ratio Idbr/Iph of wavelength continuous variable, owing between each semiconductor laser, have discreteness, so must measure to each semiconductor laser.

Now, when estimating these characteristics, measure, need suitable workload with spectroanalysis instrument etc.When considering the batch process of Wavelength variable dbr semiconductor laser instrument, the simplification that detects operation is an important topic.

The present invention carries out in order to solve above-mentioned problem of the prior art, and its purpose is to provide pick-up unit simple in structure and wavelength variable semiconductor laser fast and accurately and easy detection method, and the detection method of coherent source.

[solving the means of problem]

For achieving the above object, the 1st structure of the pick-up unit of wavelength variable semiconductor laser of the present invention is to have active area at least, the pick-up unit of the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district, it is characterized in that: comprise above-mentioned active area, the power supply of above-mentioned phase place adjustment district and above-mentioned DBR district supplying electric current, detection is from the light receiving element of the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation, and the transmission-type wavelength on can inserting from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element is selected element.

In the 1st structure of the pick-up unit of the wavelength variable semiconductor laser of the invention described above, can insert above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, active electric current for the regulation of supplying with to above-mentioned active area, at least one side of phase current that change is supplied with above-mentioned phase place adjustment district and dbr current that above-mentioned DBR district is supplied with preferably detects output intensity through the above-mentioned laser behind the above-mentioned transmission-type wavelength selection element with above-mentioned light receiving element.

The 1st detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 1st structure of the pick-up unit of the invention described above, it is characterized in that: on from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element, do not insert under the state of above-mentioned transmission-type wavelength selection element, the active electric current that change is supplied with above-mentioned active area, detect from the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation with above-mentioned light receiving element, obtain the relation of above-mentioned active electric current and above-mentioned output intensity.

The 2nd detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 1st structure of the pick-up unit of the invention described above, it is characterized in that: above-mentioned active area is supplied with constant active electric current, having inserted above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, the dbr current that change is supplied with above-mentioned DBR district, detect with above-mentioned light receiving element and to see through the output intensity that above-mentioned transmission-type wavelength is selected the above-mentioned laser behind the element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

In the 2nd detection method of the wavelength variable semiconductor laser of the invention described above, the expectation wavelength of above-mentioned wavelength variable semiconductor laser preferably sees through above-mentioned transmission-type wavelength, and to select the output intensity of the above-mentioned laser behind the element be peaked wavelength.

The 3rd detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 1st structure of the pick-up unit of the invention described above, it is characterized in that: above-mentioned active area is supplied with constant active electric current, having inserted above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect with above-mentioned light receiving element and to see through the output intensity that above-mentioned transmission-type wavelength is selected the above-mentioned laser behind the element, obtain and above-mentioned output intensity changes point corresponding an above-mentioned phase current and an above-mentioned dbr current.

In the 3rd detection method of the wavelength variable semiconductor laser of the invention described above, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current from changing point corresponding an above-mentioned dbr current and an above-mentioned phase current with above-mentioned output intensity.In addition, at this moment preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

In the 3rd detection method of the wavelength variable semiconductor laser of the invention described above, preferably change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when changing above-mentioned phase current changes an interval delta Iph of corresponding above-mentioned phase current, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current from the above-mentioned output intensity that obtains when changing above-mentioned dbr current.In addition, at this moment, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

The 4th detection method of wavelength variable semiconductor laser of the present invention is to have active area at least, the detection method of the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district, it is characterized in that: the active electric current of the regulation that above-mentioned active area is supplied with, detect the output intensity of the laser that obtains with light receiving element, obtain that the above-mentioned laser output intensity that obtains when changing the dbr current that above-mentioned DBR district is supplied with changes the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when changing the phase current that above-mentioned phase place adjustment district is supplied with changes an interval delta Iph of corresponding above-mentioned phase current, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current interval delta Idbr and above-mentioned phase current interval delta Iph.

In the 4th detection method of the wavelength variable semiconductor laser of the invention described above, the above-mentioned output intensity that the above-mentioned output intensity that obtains when above-mentioned phase current is changed obtains when changing point and above-mentioned dbr current being changed change point preferably from above-mentioned output intensity reduce become that above-mentioned output intensity increases the change point.

In the 4th detection method of the wavelength variable semiconductor laser of the invention described above, preferably, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of controlling above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio Δ Idbr/ Δ Iph.

The 2nd structure of the pick-up unit of wavelength variable semiconductor laser of the present invention is to have active area at least, the pick-up unit of the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district, it is characterized in that: comprise above-mentioned active area, the power supply of above-mentioned phase place adjustment district and above-mentioned DBR district supplying electric current, detect the laser that penetrates from above-mentioned wavelength variable semiconductor laser output intensity light receiving element and can insert from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element on 2 subharmonic (SHG) element takes place.

In the 2nd structure of the pick-up unit of the wavelength variable semiconductor laser of the invention described above, inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, best active electric current for the regulation of supplying with to above-mentioned active area, at least one side of phase current that change is supplied with above-mentioned phase place adjustment district and dbr current that above-mentioned DBR district is supplied with has been carried out the output intensity of the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element detection.

The 5th detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 2nd structure of the pick-up unit of the invention described above, it is characterized in that: on from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element, do not insert under the state of above-mentioned SHG element, the active electric current that change is supplied with above-mentioned active area, detect from the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation with above-mentioned light receiving element, obtain the relation of above-mentioned active electric current and above-mentioned output intensity.

The 6th detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 2nd structure of the pick-up unit of the invention described above, it is characterized in that: above-mentioned active area is supplied with constant active electric current, inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, the dbr current that change is supplied with above-mentioned DBR district, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

In the 6th detection method of the wavelength variable semiconductor laser of the invention described above, the expectation wavelength of above-mentioned wavelength variable semiconductor laser is peaked wavelength by the output intensity that above-mentioned SHG element has carried out the above-mentioned higher hamonic wave light of wavelength Conversion preferably.

The 7th detection method of wavelength variable semiconductor laser of the present invention is to use the detection method of wavelength variable semiconductor laser of the 2nd structure of the pick-up unit of the invention described above, it is characterized in that: above-mentioned active area is supplied with constant active electric current, inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect the output intensity of having carried out the above-mentioned higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain and a corresponding above-mentioned phase current and the above-mentioned dbr current of above-mentioned output intensity change point.

In the 7th detection method of the wavelength variable semiconductor laser of the invention described above, preferably calculate the current ratio of above-mentioned phase current and above-mentioned dbr current from changing point corresponding an above-mentioned phase current and an above-mentioned dbr current with above-mentioned output intensity.In addition, at this moment, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

In the 7th detection method of the wavelength variable semiconductor laser of the invention described above, preferably change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when above-mentioned phase current is changed changes an interval delta Iph of corresponding above-mentioned phase current, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current from the above-mentioned output intensity that obtains when above-mentioned dbr current is changed.In addition, at this moment, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

The 1st detection method of coherent source of the present invention is to comprise having active area at least, the detection method of the coherent source of (SHG) element takes place in the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district and 2 subharmonic, it is characterized in that: above-mentioned active area is supplied with constant active electric current, the dbr current that change is supplied with above-mentioned DBR district, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

In the 1st detection method of the coherent source of the invention described above, the expectation wavelength of above-mentioned wavelength variable semiconductor laser is peaked wavelength by the output intensity that above-mentioned SHG element has carried out the above-mentioned higher hamonic wave light of wavelength Conversion preferably.

The 2nd detection method of coherent source of the present invention is to comprise having active area at least, the detection method of the coherent source of (SHG) element takes place in the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district and 2 subharmonic, it is characterized in that: change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain and a corresponding above-mentioned phase current and the above-mentioned dbr current of above-mentioned output intensity change point.

In the 2nd detection method of the coherent source of the invention described above, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current from changing point corresponding an above-mentioned dbr current and an above-mentioned phase current with above-mentioned output intensity.In addition, at this moment, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

In the 2nd detection method of the coherent source of the invention described above, preferably change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when above-mentioned phase current is changed changes an interval delta Iph of corresponding above-mentioned phase current, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current from the above-mentioned output intensity that obtains when above-mentioned dbr current is changed.In addition, at this moment, preferably calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

[simple declaration of accompanying drawing]

Fig. 1 is the summary construction diagram that the pick-up unit of the variable dbr semiconductor laser instrument of the present invention's the 1st embodiment medium wavelength is shown.

Fig. 2 illustrates the active electric current of the variable dbr semiconductor laser instrument of the present invention's the 1st embodiment medium wavelength and the graph of a relation of output intensity.

Fig. 3 illustrates dbr current among the present invention the 1st embodiment and sees through the transmission-type wavelength and select the graph of a relation of the output behind the element.

Fig. 4 illustrates among the present invention the 1st embodiment to change the corresponding phase current of point and the graph of a relation of dbr current with output.

Fig. 5 illustrates among the present invention the 2nd embodiment to change the corresponding phase current of point and the graph of a relation of dbr current with output.

Fig. 6 A is that the dbr current that illustrates when dbr current is changed is selected the graph of a relation of the output behind the element with seeing through the transmission-type wavelength, Fig. 6 B be illustrate when phase current is changed dbr current with see through the transmission-type wavelength and select the graph of a relation of the output behind the element.

Fig. 7 is the summary construction diagram that the SHG blue light source that uses optical-waveguide-type QPM-SHG device among the present invention the 4th embodiment is shown.

Fig. 8 is the summary construction diagram that the pick-up unit of the variable dbr semiconductor laser instrument of the present invention's the 4th embodiment medium wavelength is shown.

Fig. 9 illustrates among the present invention the 4th embodiment to change the corresponding phase current of point and the graph of a relation of dbr current with output.

Figure 10 A is that the dbr current that illustrates when dbr current is changed is selected the graph of a relation of the output behind the element with seeing through the transmission-type wavelength, Figure 10 B be illustrate when phase current is changed dbr current with see through the transmission-type wavelength and select the graph of a relation of the output behind the element.

Figure 11 is the summary construction diagram that the pick-up unit of the variable dbr semiconductor laser instrument of the present invention's the 5th embodiment medium wavelength is shown.

Figure 12 is the graph of a relation of the output after the dbr current when dbr current and phase current are changed being shown and seeing through transmission-type wavelength selection element.

Figure 13 is the summary construction diagram that the pick-up unit of the variable dbr semiconductor laser instrument of the present invention's the 6th embodiment medium wavelength is shown.

Figure 14 is the summary construction diagram that the variable dbr semiconductor laser instrument of prior art medium wavelength is shown.

Figure 15 be illustrate the variable dbr semiconductor laser instrument of prior art medium wavelength dbr current is changed the time the Wavelength variable performance plot.

Figure 16 illustrates the phase current corresponding with mode hopping point in the prior art and the graph of a relation of dbr current.

Figure 17 is the wavelength continuous variable performance plot that the variable dbr semiconductor laser instrument of prior art medium wavelength is shown.

[inventive embodiment]

Utilize embodiment that the present invention is further specified below.

[the 1st embodiment]

Fig. 1 is the summary construction diagram that the pick-up unit of the dbr semiconductor laser instrument (to call " Wavelength variable dbr semiconductor laser instrument " in the following text) that has the Wavelength variable function among the present invention the 1st embodiment is shown.

As shown in Figure 1, from the laser that Wavelength variable dbr semiconductor laser instrument 1 penetrates, after becoming directional light, lens 2 are led to the light receiving element 3 of the output intensity that is used for detection laser.Used device with the bandwidth to the MHz as light receiving element 3.Though by using the higher light receiving element of response speed can improve the light detection speed as light receiving element 3, its light receiving area reduces.The light signal that is recorded by light receiving element 3 is stored in after A/D converter 4 is converted to digital signal in the storer in the control circuit 5.Use microcomputer as control, used 12 microcomputer.In addition, this pick-up unit also has the transmission-type wavelength selection element 6 on can inserting from Wavelength variable dbr semiconductor laser instrument 1 to the light path of light receiving element 3.

In the present embodiment, select element 6, used the dielectric multilayer film that on quartz glass substrate, forms as the transmission-type wavelength.Here, the dielectric multilayer film is TiO ₂With SiO ₂Rhythmo structure.When using the transmission-type wavelength that constitutes by the dielectric multilayer film to select element 6, select the angle of 6 pairs of laser beam axis of element by changing the transmission-type wavelength, can change the transmission peak value wavelength.At this moment, when the transmission-type wavelength selected the angle of 6 pairs of laser beam axis of element to increase, the transmission peak value wavelength moved to short wavelength side.

In the present embodiment, by used transmission-type wavelength being selected the fixed angle to laser beam axis of element 6, estimated transmitted spectrum.In the present embodiment, use 3 kinds of (sample A, B, C) transmission-type wavelength to select element 6, their maximum transmission rate (%) and half widths (nm) of reducing by half of transmissivity separately are as follows: be respectively 50% and 0.15nm among the sample A, be respectively 70% and 0.3nm among the sample B, be respectively 90% and 0.6nm among the sample C.

Wavelength variable dbr semiconductor laser instrument 1 has active area, phase place adjustment district and Bragg reflective (DBR) to distinguish this 3 zones.Active area is the zone that produces gain.Form diffraction grating in the DBR district, only light period defining or specially appointed wavelength by this diffraction grating is reflected.Therefore, when the power supply in control circuit 5 when active area supplying electric current (to call " active electric current " in the following text), just between the end face of active area side and DBR district, produce stimulated radiation.In addition, when the power supply in control circuit 5 during, rise because of there being the internal resistance temperature, thereby refractive index changes to DBR district and phase place adjustment district supplying electric current (to call " dbr current " and " phase current " in the following text).Therefore, in the DBR district, the light wavelength of reflection changes, and in phase place adjustment district, and the phase state of the resonator cavity that is made of the outgoing end face and the DBR district of active area side changes.

As described in prior art one joint, active electric current is fixed and can be obtained stair-stepping Wavelength variable characteristic when dbr current is changed.And then, phase current is changed, and dbr current is changed, obtain the Wavelength variable characteristic, current value (the A point among Figure 15 of prior art) to the step (being that output intensity changes point) that forms ladder is mapped, and can obtain the figure shown in Figure 16 of prior art.Can calculate the current ratio Idbr/Iph=0.5 of dbr current (Idbr) and phase current (Iph) from this figure, when controlling dbr current (Idbr) and phase current (Iph) simultaneously this relation is kept, can realize the wavelength continuous variable characteristic shown in Figure 17 of prior art.

Detection method to the pick-up unit that utilizes Wavelength variable dbr semiconductor laser instrument shown in Figure 1 describes below.

1) active electric current-laser output characteristic

At first, on from Wavelength variable dbr semiconductor laser instrument 1 to the light path of light receiving element 3, do not insert under the state of transmission-type wavelength selection element 6, active electric current is changed, detect from the output intensity of the laser of Wavelength variable dbr semiconductor laser instrument 1 ejaculation with light receiving element 3.Select by means of active area is supplied with active electric current, can obtain active electric current-laser output characteristic shown in Figure 2 under the element 6 non-existent states at the transmission-type wavelength.

2) wavelength of Wavelength variable dbr semiconductor laser instrument detects

Insert the transmission-type wavelength in light path and select element 6 from Wavelength variable dbr semiconductor laser instrument 1 to light receiving element 3, active electric current is set at 150mA (laser output 100mW), phase current is set at 0mA, the output characteristics of the Wavelength variable dbr semiconductor laser instrument 1 when with light receiving element 3 detections dbr current being changed.In addition, selecting the angle of element 6 (sample C: maximum transmission rate is 90%, and half width is 0.6nm) to the optical axis of the laser that penetrates from Wavelength variable dbr semiconductor laser instrument 1 by adjusting the transmission-type wavelength, is 820nm with the transmission peak value wavelength set.In addition, in the present embodiment, the expectation wavelength is set to 820 ± 0.5nm.When making dbr current when 0mA changes to 50mA,, then see through the transmission-type wavelength and select light signal (output intensity of the laser) maximum that records behind the element 6 in case the excitation wavelength of Wavelength variable dbr semiconductor laser instrument 1 becomes 820nm.The 820.5nm of the excitation wavelength of the Wavelength variable dbr semiconductor laser instrument 1 that uses in the present embodiment when the 819.5nm of dbr current during as 0mA changes to dbr current as 50mA.Figure 3 illustrates the light signal (output intensity of the laser before the A/D conversion) that at this moment records with light receiving element 3.In Fig. 3, the longitudinal axis is represented relative intensity.As shown in Figure 3, when dbr current is 25mA, detected maximum output intensity.Hence one can see that, and in the present embodiment, the dbr current corresponding with the expectation wavelength of Wavelength variable dbr semiconductor laser instrument 1 is 25mA.

3) measurement of current ratio Idbr/Iph

Shown in Figure 3 when dbr current is changed see through the transmission-type wavelength select the output intensity of the laser behind the element 6 to change point (forming the current value B1 of the step of ladder～B5) is the point of excitation wavelength generation mode hopping.That is, these output intensities change the shown in Figure 15 mode hopping point (for example A point) of point corresponding to prior art.Then phase current is set at 20mA, similarly with light receiving element 3 detect when dbr current is changed, see through the laser output intensity after the transmission-type wavelength is selected element 6.Since by the increase phase current, the refractive index in the optical waveguide, and promptly phase state changes, so output intensity changes point (B1～B5) move.And then phase current is set at 40mA, similarly with light receiving element 3 detect when dbr current is changed, see through the laser output intensity after the transmission-type wavelength is selected element 6, obtain output intensity and change point (B1～B5).In Fig. 4, show with output intensity and change point (dbr current and phase current that B1～B5) is corresponding.

The figure of Fig. 4 is with suitable at the Figure 16 shown in prior art one joint.Can calculate the current ratio Idbr/Iph of dbr current (Idbr) and phase current (Iph) from this figure, by means of DBR district and phase place adjustment district being supplied with dbr current (Idbr) and phase current (Iph) respectively, the excitation wavelength of Wavelength variable dbr semiconductor laser instrument 1 is changed continuously with this current ratio.Promptly can realize the wavelength continuous variable.In the present embodiment, Idbr/Iph=0.5 can be calculated,, the wavelength continuous variable can be realized by means of with this current ratio control dbr current (Idbr) and phase current (Iph) by Fig. 4.

Use the data processing of control circuit 5 (microcomputer) to describe to reality below.In the present embodiment, owing to used 12 microcomputer with microcomputer, can be divided into 4096 grades from 0X000 to 0XFFF with supplying with each regional electric current as control.Here, 0X represents the number of 16 systems.In addition, in the present embodiment, the maximal value of phase current and dbr current is set to about 128mA.Be that 0X020 is equivalent to 1mA.In addition, in the present embodiment, the maximal value of active electric current is set to about 256mA.Be that 0X010 is equivalent to 1mA.

The 1st kind of method (calculating) from figure

Here, active electric current be set to 0X640 (suitable 100mA, 50mW).At first phase current is set at 0X000 (0mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd (1)～Pd (112).Then, phase current is set at 0X280 (20mA) and 0X500 (40mA) respectively.Then, dbr current is changed, in the storer of data storage in control circuit 5 with Pd (1)～Pd (112).

Data with the store memory storage are carried out following operation.

1) obtains the dbr current Idbrmax (N) corresponding among Pd (1)～Pd (112) with maximal value Pd (N).Can know that thus the dbr current corresponding with the expectation wavelength of Wavelength variable dbr semiconductor laser instrument 1 is 0X320 (25mA).

2) ask the dbr current Idbr δ (N) that Pd (N+1)-Pd (N)＞δ P is set up, promptly laser output intensity changes point.Here, δ P selects the wavelength selectivity of element 6 relevant with the transmission-type wavelength of use.In the present embodiment, δ P is set to and 5% of maximum output Pd (N) suitable 0.05Pd (N).

By obtaining the figure suitable with Fig. 4 to these data mappings.Obtain the mean value of the current ratio Idbr/Iph of dbr current (Idbr) and phase current (Iph) by this figure, by means of DBR district and phase place adjustment district being supplied with dbr current (Idbr) and phase current (Iph) respectively, can realize the wavelength continuous variable with this current ratio.In the present embodiment, Idbr/Iph=0.5.

In the present embodiment, can also check the Wavelength variable characteristic and the unimodality of Wavelength variable dbr semiconductor laser instrument 1.As shown in Figure 3, when dbr current is peaked current value 0X320 (25mA) when following at the light signal that is recorded by light receiving element 3 (laser output intensity), the gained pitch of signal note increases, when 0X320 (25mA) is above, and the decline of gained pitch of signal note.In addition, change the interval substantial constant of the corresponding dbr current of point with the laser output intensity that Pd (N+1)-Pd (N)＞δ P is set up.Wavelength variable characteristic at the Wavelength variable dbr semiconductor laser instrument of measuring 1: i) not dull increase, ii) longitudinal mode is a multimode, iii) the unsettled occasion of mode hopping point (output intensity change point) during Wavelength variable can not get characteristic shown in Figure 3.

In the present embodiment, 1. increase and dull dropping characteristic by the dullness of estimating 0X320 (25mA) front and back, perhaps 2. depart from the situation of interval averages (for example 30%) significantly, can check the Wavelength variable characteristic and the unimodality of Wavelength variable dbr semiconductor laser instrument 1 by estimating interval that output intensity changes point.

The pick-up unit and the detection method of present embodiment are characterised in that: installation cost is low, and detection speed is fast.Equipment price height of the spectroanalysis instrument of Shi Yonging, and sweep velocity in the prior art and data are adopted into slow, need about the several seconds usually from being triggered to data output.In contrast, in the structure of present embodiment, the feed speed when depending on detection time Wavelength variable dbr semiconductor laser instrument 1 supplying electric current and the response speed of light receiving element 3 can detect in the time of the order of magnitude of μ sec (microsecond)～below the msec (millisecond).In fact, by using the high light receiving element 3 of response speed, can in the time of the order of magnitude of nsec (nanosecond)～below the μ sec (microsecond), detect.

In addition, the transmission-type wavelength selects element to be characterised in that: by means of making multi-layer film structure, freely the design wavelength selectivity by means of as present embodiment half width being designed to about 0.6nm, can be estimated the Wavelength variable characteristic in the Wavelength variable district about 1nm.Therefore, according to present embodiment, can measure simultaneously the Wavelength variable characteristic, with expectation wavelength corresponding dbr current and the necessary current ratio Idbr/Iph=0.5 of wavelength continuous variable.Also have,, be designed to about 1nm, can also estimate the Wavelength variable characteristic in the Wavelength variable district about 2nm by means of half width with wavelength selectivity according to present embodiment.But, when widening wavelength variable width, reduce, so wavelength variable width must be set for and the corresponding wavelength selection of detection resolution width owing to change the difference of putting the signal that records with light receiving element in output intensity.

[the 2nd embodiment]

The 2nd kind of method (slope by microcell is calculated)

In Wavelength variable dbr semiconductor laser instrument, when make phase current mode hopping point ± when changing in the scope about 10mA, mode hopping (output intensity change) does not take place in this scope.Therefore, as in the relation of this area test Idbr (max), can obtain current ratio Idbr/Iph more simply with phase current.In the present embodiment, in the structure of Fig. 1, select element 6, used sample A (maximum transmission rate 50%, half width 0.15nm) as the transmission-type wavelength.

Here, active electric current be set to 0X640 (suitable 100mA, 50mW).At first phase current is set at 0X000 (0mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd1 (1)～Pd1 (112).Then, make phase current with the spacing of 0X010 (0.5mA) from 0X000 (0mA) to 0X500 (40mA) when raising step by step, to each phase current, change dbr current step by step from 0X010 (0.5mA) to 0X700 (56mA) with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pdn (1)～Pdn (112).At this moment, ask with storer in corresponding phase current and the dbr current (Iph0, Idbr0) of maximal value Pd (N) among Pd1 (1)～Pdn (112) of storing.In the present embodiment, obtained Iph0=20mA, Idbr0=25mA.Phase current when asking light signal to be maximal value here, is in order to increase the change amount that the output intensity among resulting Pdn (1)～Pdn (112) when dbr current is changed changes point.

Below detection method is described.

At first phase current is set at 0X280 (20mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd1 (1)～Pd1 (112).Then, phase current is set at the 0X1E0 (15mA) that has reduced 5mA, similarly, is fixing under the state of this phase current, dbr current is changed to 0X700 (56mA) step by step with the spacing 0X010 (0.5mA) of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd2 (1)～Pd2 (112).Follow again, phase current is set at the 0X320 (25mA) that has increased 5mA, similarly, fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd3 (1)～Pd3 (112).

Utilization is stored in the data in the storer, each phase current is asked the dbr current when the maximal value with Pd1 (N+1)-Pd1 (N), Pd2 (N+1)-Pd2 (N), Pd3 (N+1)-Pd3 (N), promptly change the corresponding dbr current (but in the present embodiment, ignoring value) of point for negative value with laser output intensity.Figure 5 illustrates its result.Transverse axis among Fig. 5 is the phase current that changes point with respect to output intensity, and the longitudinal axis is a dbr current.The slope that connects the straight line of 3 points is exactly current ratio Idbr/Iph, and Idbr/Iph=0.5 is arranged.

In the structure of present embodiment, identical with above-mentioned the 1st embodiment, the feed speed when depending on detection time Wavelength variable dbr semiconductor laser instrument 1 supplying electric current and the response speed of light receiving element 3 can detect in the time of the order of magnitude below the msec (millisecond).

In addition, select width about the wavelength of present embodiment, its half width is very narrow, is 0.15nm.In addition, the optimum to phase current also detects.Select width by means of subtracting narrow wavelength, make in output intensity to change the difference increase of putting the signal that records with light receiving element, can improve the accuracy of detection of signal difference Pd (N+1)-Pd (N).Therefore, as present embodiment, because can detection signal difference Pd (N+1)-and dbr current (Idbr) when Pd (N) is maximal value, can calculate current ratio Idbr/Iph simply, so can be in the hope of the further shortening of detection time.

[the 3rd embodiment]

In the present embodiment, the method for calculating current ratio Idbr/Iph with the interval of laser output intensity change point is described.In the method, select element 6, used the sample B of the half width of transmitted spectrum as 0.3nm as the transmission-type wavelength.

Here, active electric current be set to 0X640 (suitable 100mA, 50mW).At first phase current is set at 0X000 (0mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pd (1)～Pd (112).Then, with dbr current be fixed on Pd (1)～Pd (112) in the corresponding Idbr (25mA) of peaked Pd (N), phase current is changed from 0X000 (0mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 3 records with A/D converter 4 then, in the storer of data storage in control circuit 5 with Pi (1)～Pi (112).

Resulting data have been shown in Fig. 6 A, B.The longitudinal axis of Fig. 6 is represented relative intensity.Ask the dbr current Idbr (max δ) that Pd (N+1)-Pd (N)＞δ P is set up by Fig. 6 A, promptly laser output intensity changes point, calculates its mean value δ Idbr (max δ) at interval.In addition, ask the phase current Iph (max δ) that Pi (N+1)-Pi (N)＞δ P is set up, calculate its mean value δ Iph (max δ) at interval by Fig. 6 B.Then, calculate the necessary current ratio Idbr/Iph=δ of wavelength continuous variable Idbr (max δ)/δ Iph (max δ) by these values.Here, δ P selects the wavelength selectivity of element 6 relevant with the transmission-type wavelength of use.In the present embodiment, δ P is set to 10% the 0.1Pd (N) that is equivalent to maximum output Pd (N).As the result of Fig. 6, try to achieve current ratio Idbr/Iph=0.5.

In the structure of present embodiment, identical with the above-mentioned the 1st and the 2nd embodiment, the feed speed when depending on detection time Wavelength variable dbr semiconductor laser instrument 1 supplying electric current and the response speed of light receiving element 3 can detect in the time of the order of magnitude below the msec (millisecond).Present embodiment is characterised in that: after dbr current is carried out 1 scanning, only scan 1 phase current and just can calculate current ratio Idbr/Iph.Therefore, can carry out the detection of Wavelength variable characteristic more at high speed, its practical effect is bigger.

[the 4th embodiment]

In the present embodiment, make the SHG blue light source on the inferior base, describe by detecting the method that blue light detects the Wavelength variable characteristic to semiconductor laser chip and Wavelength changing element are installed in.

Figure 7 illustrates the schematic configuration of the SHG blue light source that uses in the present embodiment.

As shown in Figure 7, in the SHG of present embodiment blue light source, as as the semiconductor laser of first-harmonic, used have active area 8, the AlGaAs of the 100mW level of 0.85 mu m waveband in phase place adjustment district 9 and DBR district 10 is Wavelength variable dbr semiconductor laser instrument 7.In this semiconductor laser, can change excitation wavelength by changing the dbr current that DBR district 10 is supplied with.

In addition, as Wavelength changing element, used optical-waveguide-type 2 subharmonic of accurate phase matching (following note is made " QPM ") mode that (following note is made " SHG ") device (optical-waveguide-type QPM-SHG device) 11 takes place.That is, optical-waveguide-type QPM-SHG device 11 is by using lithium niobate (LiNbO ₃) the optical crystal substrate (the X plate is mixed the LiNbO of the MgO of 5%mol ₃Substrate) optical waveguide 12 that upper surface forms and being used to compensate first-harmonic and higher hamonic wave propagation constant difference, with periodic polarized reversal zone 13 formations of optical waveguide 12 quadratures.Optical waveguide 12 forms by means of carry out proton exchange in pyrophosphoric acid.In addition, periodic polarized reversal zone 13 is by means of the LiNbO that mixes the MgO of 5%mol at the X plate ₃Substrate+x surface forms comb electrode and parallel pole, and between comb electrode and parallel pole, apply the electric field about 5kV and form.Mix the LiNbO of the MgO of 5%mol at the X plate ₃On the substrate, on optical waveguide formation face, formed by SiO ₂The diaphragm that constitutes.In the SHG of present embodiment blue light source, consistent by means of the wavelength that makes first-harmonic with the phase matching wavelengths of optical-waveguide-type QPM-SHG device 11, realized wavelength Conversion.At this moment, to obtaining the wavelength of maximum conversion efficiency, the width of allowing of the wavelength that conversion efficiency reduces by half is about 0.1nm.

Wavelength variable dbr semiconductor laser instrument 7 and optical-waveguide-type QPM-SHG device 11, be fixed on this Asia base 14 with the mode that inferior base 14 joins with active layer and the face that forms optical waveguide 12, couple directly to the optical waveguide 12 of optical-waveguide-type QPM-SHG device 11 from the laser of the outgoing end face ejaculation of Wavelength variable dbr semiconductor laser instrument 7.

Make Wavelength variable dbr semiconductor laser instrument 7 luminous on one side, Yi Bian carry out the optically-coupled adjustment, feasible laser output to 100mW has the laser coupled of 60mW to optical waveguide 12.The dbr current and the phase current of control Wavelength variable dbr semiconductor laser instrument 7 are fixed in the phase matching wavelengths permission of optical-waveguide-type QPM-SHG device 11 its excitation wavelength.Now, the wavelength that has obtained about 10mW is the blue light of 425nm.

In the present embodiment, the method for measuring the current ratio of necessary dbr current of wavelength continuous variable and phase current by the output that detects the higher hamonic wave light (blue light) that is obtained by wavelength Conversion is described.In case the wavelength continuous variable is accomplished, just can stably control blue light output (people such as Hengshan Mountain: the electric paper will C of association, Vol.120-C, P398 put down into 12 years).

The phase matching wavelengths of optical-waveguide-type QPM-SHG device 11 allows that width is about 0.1nm.Promptly detect blue light, see through the transmission-type wavelength with detection among above-mentioned the 1st～the 3rd embodiment and select the output intensity of the laser behind the element that equivalent effect is arranged, can consider to replace the transmission-type wavelength to select elements with optical-waveguide-type QPM-SHG device 11.In the present embodiment, the method to the Wavelength variable characteristic of the Wavelength variable dbr semiconductor laser instrument 7 that detects the SHG blue light source that is made of Wavelength variable dbr semiconductor laser instrument 7 and optical-waveguide-type QPM-SHG device 11 describes.

Below the detection method that is equivalent to above-mentioned the 2nd embodiment is described.Figure 8 illustrates the pick-up unit that uses in the present embodiment.

As shown in Figure 8, the blue light from Wavelength variable dbr semiconductor laser instrument 7 penetrates is led to light receiving element 17 after lens 16 become directional light.This pick-up unit has the first-harmonic that can insert from lens 16 to light receiving element on 17 the light path by color filter 18, and the first-harmonic that does not carry out wavelength Conversion is blocked by color filter 18 by this first-harmonic.Therefore, light receiving element 17 can only will detect as light signal through the blue light that wavelength Conversion obtains.The light signal that is recorded by light receiving element 17 is converted in the storer that deposits in after the digital signal in the control circuit 20 by A/D converter 19.

Here, active electric current be set to 0XA00 (suitable 160mA, 100mW).Because the blue light that obtains through wavelength Conversion is output as about 10mW the laser of 100mW, thus in order to improve the mensuration precision, with supplying electric current set greatly some.At first phase current is set at 0X000 (0mA), under the state that this phase current is fixed, dbr current is changed step by step with the spacing of 0X010 (0.5mA) from 0X010 (0.5mA) to 0X700 (56mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω 1 (1)～Pd ₂In the storer of data storage in control circuit 20 of ω 1 (112).Then, make phase current with the spacing of 0X010 (0.5mA) from 0X000 (0mA) to 0X500 (40mA) when raising step by step, to each phase current, change dbr current step by step from 0X010 (0.5mA) to 0X700 (56mA) with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω n (1)～Pd ₂In the storer of data storage in control circuit 20 of ω n (112).At this moment, ask with storer in the Pd that stores ₂ω 1 (1)～Pd ₂Maximal value Pd among the ω n (112) ₂Phase current and dbr current (Iph0, Idbr0) that ω (N) is corresponding.In the present embodiment, obtained Iph0=20mA, Idbr0=25mA.Phase current when asking light signal to be maximal value here, is in order to increase resulting Pd when dbr current is changed ₂ω n (1)～Pd ₂Output intensity among the ω n (112) changes the change amount of point.

Below detection method is described.

At first phase current is set at 0X280 (20mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω 1 (1)～Pd ₂In the storer of data storage in control circuit 20 of ω 1 (112).Then, phase current is set at the 0X1E0 (15mA) that has reduced 5mA, similarly, is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω 2 (1)～Pd ₂In the storer of data storage in control circuit 20 of ω 2 (112).Follow again, phase current is set at the 0X320 (25mA) that has increased 5mA, similarly, fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω 3 (1)～Pd ₂In the storer of data storage in control circuit 20 of ω 3 (112).

Utilization is stored in the data in the storer, and each phase current is asked and Pd ₂ω 1 (N+1)-Pd ₂ω 1 (N), Pd ₂ω 2 (N+1)-Pd ₂ω 2 (N), Pd ₂ω 3 (N+1)-Pd ₂Dbr current when ω 3 (N) is maximal value promptly changes the corresponding dbr current (but in the present embodiment, ignoring the value for negative value) of point with output intensity.Figure 9 illustrates its result.The slope that connects the straight line of 3 points is exactly current ratio Idbr/Iph, and Idbr/Iph=0.5 is arranged.

The result of Fig. 9 and the result of Fig. 5 are roughly the same.In the SHG blue light source that constitutes by Wavelength variable dbr semiconductor laser instrument and optical-waveguide-type QPM-SHG device, replace and use the transmission-type wavelength to select element, by detecting the blue light output that obtains through wavelength Conversion, similarly can try to achieve the Wavelength variable characteristic of Wavelength variable dbr semiconductor laser instrument, can easily obtain the necessary current ratio Idbr/Iph of wavelength continuous variable simultaneously.

In addition, adopt and the suitable detection method of above-mentioned the 3rd embodiment, also can detect the Wavelength variable characteristic.Below the method is described.

In the occasion that adopts the detection method suitable, need when phase current is changed, detect output intensity and change point with above-mentioned the 3rd embodiment.Therefore, when the wavelength of the phase matching of optical-waveguide-type QPM-SHG device being allowed width hour, can not detect output intensity and change point.In the present embodiment, used leement duration 5mm, wavelength is allowed the optical-waveguide-type QPM-SHG device of width 0.2nm.

Here, active electric current be set to 0XA00 (suitable 160mA, 100mW).Because the blue light that obtains through wavelength Conversion is output as about 10mW the laser of 100mW, thus in order to improve measuring accuracy, with supplying electric current set greatly some.At first phase current is set at 0X000 (0mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 19 ₂ω (1)～Pd ₂In the storer of data storage in control circuit 20 of ω (112).Then, dbr current is fixed on and Pd ₂ω (1)～Pd ₂Peaked Pd among the ω (112) ₂The Idbr (25mA) that ω (N) is corresponding makes phase current change step by step from 0X000 (0mA) to 0X700 (56mA) with the spacing of 0X010 (0.5mA).Detect the blue light that obtains through wavelength Conversion with light receiving element 17 then, and should detected conversion of signals be digital signal, with Pi with A/D converter 19 ₂ω (1)～Pi ₂In the storer of data storage in control circuit 20 of ω (112).

The data that obtain have been shown in Figure 10 A, B.The longitudinal axis of Figure 10 is represented relative intensity.Ask by Figure 10 A and to make Pd ₂ω (N+1)-Pd ₂The dbr current Idbr (max δ) that ω (N)＞δ P sets up, promptly output intensity changes point, calculates its mean value δ Idbr (max δ) at interval.In addition, ask by Figure 10 B and make Pi ₂ω (N+1)-Pi ₂The phase current Iph (max δ) that ω (N)＞δ P sets up calculates its mean value δ Iph (max δ) at interval.Then, calculate the necessary current ratio Idbr/Iph=δ of wavelength continuous variable Idbr (max δ)/δ Iph (max δ) by these values.In the present embodiment, δ P is set to 20% the 0.2Pd (N) that is equivalent to maximum output Pd (N).As the result of Figure 10, try to achieve current ratio Idbr/Iph=0.5.

Also have, though in the present embodiment the SHG blue light source that is made of Wavelength variable dbr semiconductor laser instrument 7 and optical-waveguide-type QPM-SHG device 11 is illustrated, in the SHG blue light source that constitutes by Wavelength variable dbr semiconductor laser instrument and build QPM-SHG device, also can obtains same effect.Also have, utilize the occasion of the phase matching type SHG device of birefringence, also can obtain same effect in employing.

As mentioned above, in the detection of the SHG blue light source that constitutes by Wavelength variable dbr semiconductor laser instrument 7 and optical-waveguide-type QPM-SHG device 11, do not need single Wavelength variable dbr semiconductor laser instrument 7 is detected, by means of estimating the wavelength conversion characteristics that the SHG blue light source after making up is installed, can detect in the lump: the 1. output characteristics of Wavelength variable dbr semiconductor laser instrument, Wavelength variable characteristic etc., 2. be used to realize the stable necessary current ratio of wavelength continuous variable of SHG blue light source output, and detect 1. simultaneously and 2..Because this result also can make shorten detection time, so its practical effect is bigger.

In addition, present embodiment is characterised in that as shown in figure 10, the output that output intensity changes point changes often greatly.The state that output when the Fig. 6 among above-mentioned the 3rd embodiment shows the laser that penetrates from Wavelength variable dbr semiconductor laser instrument 1 and directly received by light receiving element 3 changes.What the output of the higher hamonic wave light that obtains in the SHG blue light source and output as the semiconductor laser of first-harmonic changed square is directly proportional.Therefore, carrying out the occasion of light-receiving with the higher hamonic wave light that obtains through 2 subharmonic as light signal, the output that can make output intensity change point changes and increases.Thereby also can improve accuracy of detection.

[the 5th embodiment]

In the present embodiment, to not using the transmission-type wavelength to select element to ask the method for the current ratio Idbr/Iph of necessary dbr current of wavelength continuous variable and phase current to describe.

Wavelength variable dbr semiconductor laser instrument has active area, phase place adjustment district and Bragg reflective (DBR) and distinguishes this 3 zones.When DBR district and phase place adjustment district are supplied with dbr current and phase current respectively, rise because of there being the internal resistance temperature, thereby refractive index changes.Therefore, change in the light wavelength of DBR district reflection, and in phase place adjustment district, the phase state of the resonator cavity that is made of the outgoing end face and the DBR district of active area side changes.Making dbr current, phase current why can obtain stair-stepping Wavelength variable characteristic when changing, be because phase state changes, thereby the number of the ripple in the resonator cavity has had the cause that changes.Because when the number change of the phase state of the ripple in the resonator cavity and ripple, the sharp state of penetrating of Wavelength variable dbr semiconductor laser instrument changes, so the output intensity that obtains also changes.

In Figure 11, show the pick-up unit that uses in the present embodiment.In the pick-up unit of present embodiment, do not need the transmission-type wavelength to select element.

As shown in figure 11, the laser from Wavelength variable dbr semiconductor laser instrument 21 penetrates directly is led to light receiving element 23 after lens 22 become directional light.The light signal that is recorded by light receiving element 23 is stored in after A/D converter 24 is converted to digital signal in the storer in the control circuit 25.

In Figure 12, the active electric current that shows Wavelength variable dbr semiconductor laser instrument is set at 100mA, the output intensity when dbr current and phase current are changed.In Figure 12, the longitudinal axis is represented relative intensity.C point among Figure 12 is the point that the number of ripple changes, and is equivalent to the A point shown in Figure 15 of prior art.Because the output intensity of trying to achieve in above-mentioned the 3rd embodiment change point is the C point among Figure 12, so can calculate the current ratio Idbr/Iph of necessary dbr current of wavelength continuous variable and phase current by the current intervals of asking this C to order to dbr current and phase current.

Below the actual detection method is described.Here, active electric current be set to 0X640 (suitable 100mA, 50mW).At first phase current is set at 0X000 (0mA), is fixing under the state of this phase current, dbr current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).To be converted to digital signal by the light signal that light receiving element 23 records with A/D converter 24 then, in the storer of data storage in control circuit 25 with Pd (1)～Pd (112).Then, dbr current is set at 0X000 (0mA), phase current is changed from 0X010 (0.5mA) to 0X700 (56mA) step by step with the spacing of 0X010 (0.5mA).Then, will be converted to digital signal by the light signal that light receiving element 23 records, in the storer of data storage in control circuit 25 with Pi (1)～Pi (112) with A/D converter 24.

The value that is equivalent to point that the C of Figure 12 orders and is Pd (1)～Pd (112) and Pi (1)～Pi (112) becomes positive point by negative.Obtain by the positive point of negative change, calculate the mean value δ Idbr (±) and the δ Iph (±) at this interval.Calculate wavelength continuous variable necessary current ratio Idbr/Iph=δ Idbr (±)/δ Iph (±) by these values.In the present embodiment, try to achieve current ratio Idbr/Iph=0.5.

In the structure of present embodiment, the feed speed when depending on detection time Wavelength variable dbr semiconductor laser instrument 21 supplying electric currents and the response speed of light receiving element 23 can detect in the time of the order of magnitude below the msec (millisecond).In addition, after dbr current being carried out 1 scanning, only scan 1 phase current and just can calculate current ratio Idbr/Iph.Also have, change interval constant of point, can check general Wavelength variable characteristic by check output intensity in the Wavelength variable district.If this interval instability just means that longitudinal mode is a multimode, or the Wavelength variable instability.

In addition, the detection method of present embodiment does not need the transmission-type wavelength to select element, so it is the detection method that can utilize the practicality of the device identical with the pick-up unit of conventional semiconductor laser instrument owing to different with above-mentioned the 1st～the 3rd embodiment.But output variation shown in Figure 12 depends on the outgoing end face of Wavelength variable dbr semiconductor laser instrument 21 and the diffraction light quantity in DBR district.Particularly in high output semiconductor laser,, change very difficult so detect its output because the reflectivity of outgoing end face is little.In the structure of above-mentioned the 1st～the 4th embodiment, the signal that can detect is big, and its change amount is also big.Also have, according to above-mentioned the 1st～the 4th embodiment, can be in the hope of phase matching wavelengths etc., and near the current ratio Idbr/Iph the expectation wavelength.

In addition, according to the detection method of present embodiment, in the SHG blue light source that constitutes by Wavelength variable dbr semiconductor laser instrument and optical-waveguide-type QPM-SHG device, also can obtain same effect.But, in the SHG blue light source, because when the excitation wavelength of Wavelength variable dbr semiconductor laser instrument is consistent with the phase matching wavelengths of optical-waveguide-type QPM-SHG device, the semiconductor laser that obtains from optical waveguide outgoing portion reduces because of wavelength Conversion, so the output that also can take place to be caused by this effect changes.Therefore, can carry out with higher precision in the detection of the wave band that departs from phase matching wavelengths.By means of detecting the blue light output that obtains through wavelength Conversion, similarly can obtain the Wavelength variable characteristic, and can easily try to achieve the necessary current ratio Idbr/Iph of wavelength continuous variable.

[the 6th embodiment]

In above-mentioned the 1st～the 3rd embodiment, select the method for the Wavelength variable characteristic of element testing Wavelength variable dbr semiconductor laser instrument to be illustrated to using the transmission-type wavelength.In addition, in above-mentioned the 4th embodiment,, check that the method for the Wavelength variable characteristic of Wavelength variable dbr semiconductor laser instrument is illustrated to carrying out the blue light that wavelength Conversion obtains through optical-waveguide-type QPM-SHG device by detecting.By above explanation as can be known, replace the transmission-type wavelength to select element also can detect the Wavelength variable characteristic of Wavelength variable dbr semiconductor laser instrument with optical-waveguide-type QPM-SHG device.But, owing to when using optical-waveguide-type QPM-SHG device, the laser light that penetrates from Wavelength variable dbr semiconductor laser instrument is coupled to the optical waveguide of optical-waveguide-type QPM-SHG device, so very inconvenient in the use.So in the present embodiment, the method for using build QPM-SHG device to detect the Wavelength variable characteristic of Wavelength variable dbr semiconductor laser instrument is described.

The method for making of build QPM-SHG device at first is described.At the thick Z cutting LiTaO of 1mm ₃Form periodic polarized reversal zone on the substrate.Periodic polarized reversal zone is by means of cutting LiTaO at Z ₃Substrate+z surface forms comb electrode, its-the z surface forms backplate, between comb electrode and backplate, apply the electric field about 20kV and form.The polarization reversal cycle is 10 μ m, forms the accurate phase-matching condition of 3 dimensions.Leement duration is 3mm, and to obtaining the wavelength of maximum conversion efficiency, the width of allowing of the wavelength that conversion efficiency reduces by half is about 0.3nm.Allowing that width depends on leement duration, is 1mm by making its length, can broadening to about the 1nm.

In Figure 13, show the pick-up unit that uses in the present embodiment.

As shown in figure 13, the laser that penetrates from Wavelength variable dbr semiconductor laser instrument 26 becomes directional light through lens 27, converges on the build QPM-SHG device 28.The laser that converges on the build QPM-SHG device 28 carries out wavelength Conversion there, becomes blue light (higher hamonic wave light).Blue light is led to light receiving element 31 after lens 29 become directional light.In the present embodiment, used leement duration to be 3mm, allowed that width is the sample of 0.3nm.This pick-up unit is in that 31 light path is provided with first-harmonic by color filter 30 from lens 29 to light receiving element, and the first-harmonic that does not carry out wavelength Conversion is covered by color filter 30 by this first-harmonic.Therefore, light receiving element 31 can only will detect as light signal through the blue light that wavelength Conversion obtains.

In the structure of present embodiment, owing to the output power of the blue light that obtains by means of build QPM-SHG device 28 is little, thus strengthened the pull-up resistor of light receiving element 31, to improve sensitivity.Be focused at the first-harmonic on the build QPM-SHG device, with the occasion comparison of optical-waveguide-type QPM-SHG device, because power density is little, and interaction length is short, so conversion efficiency is low.Therefore, the response speed of light receiving element is compared with the response speed of using in above-mentioned the 1st embodiment, slow 2 orders of magnitude.The light signal that is recorded by light receiving element 31 is converted to digital signal by A/D converter 32, deposits in the storer in the control circuit 33.Use microcomputer as control, used 12 microcomputer.

Below detection method is described.

Detect blue light, see through the transmission-type wavelength with detection among above-mentioned the 1st～the 3rd embodiment and select the output intensity of the laser behind the element that equivalent effect is arranged, can consider to replace the transmission-type wavelength to select elements with build QPM-SHG device 28.Therefore, can use the method identical to detect the Wavelength variable characteristic of Wavelength variable dbr semiconductor laser instrument 26 with above-mentioned the 4th embodiment.

Below the detection method suitable with above-mentioned the 2nd embodiment described simply.

Here, active electric current is set to 160mA (quite 100mW).Be output as about 100 μ W through blue light that wavelength Conversion obtains laser 100mW.At first phase current is set at 0mA, is fixing under the state of this phase current, dbr current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω 1 (1)～Pd ₂In the storer of data storage in control circuit 33 of ω 1 (N).Then, making phase current when 0mA to 40mA raises,, dbr current is changed from 0mA to 50mA to each phase current.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω n (1)～Pd ₂In the storer of data storage in control circuit 33 of ω n (N).At this moment, ask with storer in store by Pd ₂ω 1 (1) is to Pd ₂The phase current of the maximal value correspondence among the ω n (N) and dbr current (Iph0, Idbr0).

Phase current is set at Iph0, is fixing under the state of this phase current, dbr current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω 1 (1)～Pd ₂In the storer of data storage in control circuit 33 of ω 1 (N).Then, phase current is set at Iph0-5mA, similarly, is fixing under the state of this phase current, dbr current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω 2 (1)～Pd ₂In the storer of data storage in control circuit 33 of ω 2 (N).Follow again, phase current is set at Iph0+5mA, similarly, under the state that this phase current is fixed, dbr current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω 3 (1)～Pd ₂In the storer of data storage in control circuit 33 of ω 3 (N).

Utilization is stored in the data in the storer, and each phase current is asked and Pd ₂ω 1 (N+1)-Pd ₂ω 1 (N), Pd ₂ω 2 (N+1)-Pd ₂ω 2 (N), Pd ₂ω 3 (N+1)-Pd ₂Dbr current when ω 3 (N) is maximal value promptly changes the corresponding dbr current (but in the present embodiment, ignoring the value for negative value) of point with output intensity.In view of the above, can obtain the result identical with Fig. 9.The slope that connects the straight line of 3 points is exactly current ratio Idbr/Iph.

In addition, adopt and the suitable detection method of above-mentioned the 3rd embodiment, also can detect the Wavelength variable characteristic.Below the method is described.

Here, active electric current is set to 160mA (quite 100mW).At first phase current is set at 0mA, is fixing under the state of this phase current, dbr current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pd with A/D converter 32 ₂ω (1)～Pd ₂In the storer of data storage in control circuit 33 of ω (N).Then, dbr current is fixed on Pd ₂ω (N) is peaked Idbrmax, and phase current is changed from 0mA to 50mA.Detect the blue light that obtains through wavelength Conversion with light receiving element 31 then, and should detected conversion of signals be digital signal, with Pi with A/D converter 32 ₂ω (1)～Pi ₂In the storer of data storage in control circuit 33 of ω (N).

According to the above, can obtain the result identical with Figure 10 A, B.Ask by Figure 10 A and to make Pd ₂ω (N+1)-Pd ₂The dbr current Idbr (max δ) that ω (N)＞δ P sets up, promptly output intensity changes point, calculates its mean value δ Idbr (max δ) at interval.In addition, ask by Figure 10 B and make Pi ₂ω (N+1)-Pi ₂The phase current Iph (max δ) that ω (N)＞δ P sets up calculates its mean value δ Iph (max δ) at interval.Then, calculate the necessary current ratio Idbr/Iph=δ of wavelength continuous variable Idbr (max δ)/δ Iph (max δ) by these values.

In addition, in the present embodiment, the method for using build QPM-SHG device to detect Wavelength variable dbr semiconductor laser instrument is illustrated.Build QPM-SHG device is characterised in that to be made easily, and cost is low.In addition, the feature of build QPM-SHG device also is, by means of cutting and grinding, can change wavelength accurately after element is made and select width (allowing width).The longitudinal mode spacing of Wavelength variable dbr semiconductor laser instrument (mode hopping at interval) depends on cavity length.Therefore, the method for present embodiment is selecting the best to allow that under the occasion of width be effective method.

In addition, the same with above-mentioned the 4th embodiment in the present embodiment, owing to utilized SHG,, output intensity changes greatly so changing the output of point.Carrying out the occasion of light-receiving with the higher hamonic wave light that obtained by 2 subharmonic as light signal, the output that can make output intensity change point changes and increases.Thereby also can improve accuracy of detection.

[effect of invention]

As mentioned above, according to the present invention, by means of have at least active area, phase place adjustment district and In the checkout gear of the wavelength variable semiconductor laser in Bragg reflective (DBR) district, bag Draw together the power supply of above-mentioned active area, above-mentioned phase place adjustment district and above-mentioned DBR district being supplied with electric current; Inspection Survey is from the light-receiving unit of the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation Part; And can insert from above-mentioned wavelength variable semiconductor laser to the light of above-mentioned light receiving element Transmission-type wavelength selectors on the road is extremely above-mentioned from above-mentioned wavelength variable semiconductor laser Inserted on the light path of light receiving element under the state of above-mentioned transmission-type wavelength selectors, for The active electric current of the regulation of supplying with to above-mentioned active area changes above-mentioned phase place adjustment district is supplied with At least one party of phase current and dbr current that above-mentioned DBR district is supplied with uses above-mentioned light-receiving Element testing sees through the output intensity of the above-mentioned laser behind the above-mentioned transmission-type wavelength selectors, asks Change point corresponding phase current and dbr current with output intensity, can simply and at high speed examine Survey wavelength variable stability and the wavelength continuous variable institute of Wavelength variable dbr semiconductor laser instrument Essential current ratio Idbr/Iph etc.

Claims (27)

1. the pick-up unit of a wavelength variable semiconductor laser, it is the pick-up unit that has the wavelength variable semiconductor laser in active area, phase place adjustment district and Bragg reflective (DBR) district at least, it is characterized in that, comprising:

Power supply to above-mentioned active area, above-mentioned phase place adjustment district and above-mentioned DBR district supplying electric current;

Detection is from the light receiving element of the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation; And

Transmission-type wavelength on can inserting from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element is selected element.

2. the pick-up unit of wavelength variable semiconductor laser as claimed in claim 1 is characterized in that:

Having inserted above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, active electric current for the regulation of supplying with to above-mentioned active area, at least one side of phase current that change is supplied with above-mentioned phase place adjustment district and dbr current that above-mentioned DBR district is supplied with detects output intensity through the above-mentioned laser behind the above-mentioned transmission-type wavelength selection element with above-mentioned light receiving element.

3. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 1, it is characterized in that:

On from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element, do not insert under the state of above-mentioned transmission-type wavelength selection element, the active electric current that change is supplied with above-mentioned active area, detect from the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation with above-mentioned light receiving element, obtain the relation of above-mentioned active electric current and above-mentioned output intensity.

4. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 1, it is characterized in that:

Above-mentioned active area is supplied with constant active electric current, having inserted above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, the dbr current that change is supplied with above-mentioned DBR district, detect with above-mentioned light receiving element and to see through the output intensity that above-mentioned transmission-type wavelength is selected the above-mentioned laser behind the element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

5. the detection method of wavelength variable semiconductor laser as claimed in claim 4 is characterized in that:

The expectation wavelength of above-mentioned wavelength variable semiconductor laser is to see through above-mentioned transmission-type wavelength to select the output intensity of the above-mentioned laser behind the element be peaked wavelength.

6. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 1, it is characterized in that:

Above-mentioned active area is supplied with constant active electric current, having inserted above-mentioned transmission-type wavelength in the light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element selects under the state of element, change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect with above-mentioned light receiving element and to see through the output intensity that above-mentioned transmission-type wavelength is selected the above-mentioned laser behind the element, obtain and above-mentioned output intensity changes point corresponding an above-mentioned phase current and an above-mentioned dbr current.

7. the detection method of wavelength variable semiconductor laser as claimed in claim 6 is characterized in that:

Calculate the current ratio of above-mentioned dbr current and above-mentioned phase current by changing point corresponding above-mentioned dbr current and above-mentioned phase current with above-mentioned output intensity.

8. the detection method of wavelength variable semiconductor laser as claimed in claim 6 is characterized in that:

Change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when above-mentioned phase current is changed changes an interval delta Iph of corresponding above-mentioned phase current from the above-mentioned output intensity that obtains when above-mentioned dbr current is changed, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current.

9. as the detection method of claim 7 or 8 described wavelength variable semiconductor lasers, it is characterized in that:

Calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

10. the detection method of a wavelength variable semiconductor laser, it is the detection method that has the wavelength variable semiconductor laser in active area, phase place adjustment district and Bragg reflective (DBR) district at least, it is characterized in that:

The active electric current of the regulation that above-mentioned active area is supplied with detects the output intensity of the laser that obtains with light receiving element,

Obtain that the above-mentioned laser output intensity that obtains when changing the dbr current that above-mentioned DBR district is supplied with changes the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when changing the phase current that above-mentioned phase place adjustment district is supplied with changes an interval delta Iph of corresponding above-mentioned phase current

Calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current interval delta Idbr and above-mentioned phase current interval delta Iph.

11. the detection method of wavelength variable semiconductor laser as claimed in claim 10 is characterized in that:

The above-mentioned output intensity that the above-mentioned output intensity that obtains when above-mentioned phase current is changed obtains when changing point and above-mentioned dbr current being changed change point be from above-mentioned output intensity reduce become that above-mentioned output intensity increases the change point.

12. the detection method of wavelength variable semiconductor laser as claimed in claim 10 is characterized in that:

By means of controlling above-mentioned dbr current and above-mentioned phase current, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously with above-mentioned current ratio Δ Idbr/ Δ Iph.

13. the pick-up unit of a wavelength variable semiconductor laser, it is the pick-up unit that has the wavelength variable semiconductor laser in active area, phase place adjustment district and Bragg reflective (DBR) district at least, it is characterized in that, comprising:

Power supply to above-mentioned active area, above-mentioned phase place adjustment district and above-mentioned DBR district supplying electric current;

Detection is from the light receiving element of the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation; And

(SHG) element takes place in 2 subharmonic on can inserting from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element.

14. the pick-up unit of wavelength variable semiconductor laser as claimed in claim 13 is characterized in that:

Inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, active electric current for the regulation of supplying with to above-mentioned active area, at least one side of phase current that change is supplied with above-mentioned phase place adjustment district and dbr current that above-mentioned DBR district is supplied with has been carried out the output intensity of the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element detection.

15. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 13, it is characterized in that:

On from above-mentioned wavelength variable semiconductor laser to the light path of above-mentioned light receiving element, do not insert under the state of above-mentioned SHG element, the active electric current that change is supplied with above-mentioned active area, detect from the output intensity of the laser of above-mentioned wavelength variable semiconductor laser ejaculation with above-mentioned light receiving element, obtain the relation of above-mentioned active electric current and above-mentioned output intensity.

16. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 13, it is characterized in that:

Above-mentioned active area is supplied with constant active electric current, inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, the dbr current that change is supplied with above-mentioned DBR district, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

17. the detection method of wavelength variable semiconductor laser as claimed in claim 16 is characterized in that:

The expectation wavelength of above-mentioned wavelength variable semiconductor laser is that the output intensity of having carried out the above-mentioned higher hamonic wave light of wavelength Conversion by above-mentioned SHG element is peaked wavelength.

18. the detection method of a wavelength variable semiconductor laser, it is to use the detection method of the wavelength variable semiconductor laser of the described pick-up unit of claim 13, it is characterized in that:

Above-mentioned active area is supplied with constant active electric current, inserted under the state of above-mentioned SHG element in light path from above-mentioned wavelength variable semiconductor laser to above-mentioned light receiving element, change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect the output intensity of having carried out the above-mentioned higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain and a corresponding above-mentioned phase current and the above-mentioned dbr current of above-mentioned output intensity change point.

19. the detection method of wavelength variable semiconductor laser as claimed in claim 18 is characterized in that:

Calculate the current ratio of above-mentioned phase current and above-mentioned dbr current from changing point corresponding above-mentioned phase current and above-mentioned dbr current with above-mentioned output intensity.

20. the detection method of wavelength variable semiconductor laser as claimed in claim 18 is characterized in that:

Change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when above-mentioned phase current is changed changes an interval delta Iph of corresponding above-mentioned phase current from the above-mentioned output intensity that obtains when above-mentioned dbr current is changed, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current.

21. the detection method as claim 19 or 20 described wavelength variable semiconductor lasers is characterized in that:

Calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

22. the detection method of a coherent source, it be comprise have active area at least, the coherent source of (SHG) element takes place for the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district and 2 subharmonic detection method, it is characterized in that:

Above-mentioned active area is supplied with constant active electric current, the dbr current that change is supplied with above-mentioned DBR district, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain the above-mentioned dbr current corresponding with the expectation wavelength of above-mentioned wavelength variable semiconductor laser.

23. the detection method of coherent source as claimed in claim 22 is characterized in that:

The expectation wavelength of above-mentioned wavelength variable semiconductor laser is that the output intensity of having carried out the above-mentioned higher hamonic wave light of wavelength Conversion by above-mentioned SHG element is peaked wavelength.

24. the detection method of a coherent source, it be comprise have active area at least, the coherent source of (SHG) element takes place for the wavelength variable semiconductor laser in phase place adjustment district and Bragg reflective (DBR) district and 2 subharmonic detection method, it is characterized in that:

Change phase current that above-mentioned phase place adjustment district is supplied with and the dbr current that above-mentioned DBR district is supplied with independently respectively, detect the output intensity of having carried out the higher hamonic wave light of wavelength Conversion by above-mentioned SHG element with above-mentioned light receiving element, obtain and a corresponding above-mentioned phase current and the above-mentioned dbr current of above-mentioned output intensity change point.

25. the detection method of coherent source as claimed in claim 24 is characterized in that:

Calculate the current ratio of above-mentioned dbr current and above-mentioned phase current from changing point corresponding above-mentioned dbr current and above-mentioned phase current with above-mentioned output intensity.

26. the detection method of coherent source as claimed in claim 24 is characterized in that:

Change the interval delta Idbr of the corresponding above-mentioned dbr current of point and the above-mentioned output intensity that obtains when above-mentioned phase current is changed changes an interval delta Iph of corresponding above-mentioned phase current from the above-mentioned output intensity that obtains when above-mentioned dbr current is changed, calculate the current ratio Δ Idbr/ Δ Iph of above-mentioned dbr current and above-mentioned phase current.

27. the detection method as claim 25 or 26 described coherent sources is characterized in that:

Calculate the current ratio of above-mentioned dbr current and above-mentioned phase current,, the excitation wavelength of above-mentioned wavelength variable semiconductor laser is changed continuously by means of control above-mentioned dbr current and above-mentioned phase current with above-mentioned current ratio.

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