CN101247019B

CN101247019B - Semiconductor pump laser

Info

Publication number: CN101247019B
Application number: CN2008100707746A
Authority: CN
Inventors: 吴砺; 卢秀爱
Original assignee: Photop Technologies Inc
Current assignee: Photop Technologies Inc
Priority date: 2008-03-19
Filing date: 2008-03-19
Publication date: 2011-12-28
Anticipated expiration: 2028-03-19
Also published as: CN101247019A

Abstract

The present invention discloses a semiconductor pumping laser which comprises of semiconductor laser pumping source, optical coupling system and laser cavity. The laser cavity comprises of front and rear cavity plates, laser gain medium, and optical elements except laser gain medium, wherein, the laser gain medium comprises of at least two slices of laser gain medium with different doped ion concentration or different absorption coefficient, different laser gain medium arranged from small to large by doped ion concentration or absorption coefficient in incidence direction of pumping source, absorbing partial pumping light by laser gain medium with low doped ion concentration, the other parts of pumping light are absorbed by laser gain medium with higher doped ion concentration, the hot lens effect of laser gain medium with high doped ion concentration is reduced and the absorption of pumping light is enhanced, so the semiconductor pumping laser suitable for working in broader pumping wavelength and broad temperature is obtained.

Description

A kind of semiconductor pump laser

Technical field

The present invention relates to field of lasers, relate in particular to a kind of employing and ooze the gain medium of assorted concentration and the semiconductor pump laser that other optical elements constitute.

Background technology

Semiconductor pump laser comprises and partly leads laser pumping source 1, optical coupling system 2 and laser cavity 3 as shown in Figure 1,

chamber sheet

33,36, gain medium 34 and other optical elements 35 etc. before and after laser cavity 3 comprises.Wherein the absorption coefficient of gain medium 34 changes with its dopant ion change in concentration, usually in the change in concentration scope when not being very big, gain medium absorbs half-peak breadth and almost remains unchanged, and the gain medium absorption coefficient improves with doping content.See the gain medium absorption coefficient curve of different dopant ion concentration shown in Figure 2 again, under identical Laser Experiments condition, adopt the loss of material identical, the absorption coefficient curve a that dopant ion concentration is low, the absorption coefficient curve b that dopant ion concentration is high, the absorption coefficient at the gain medium peak value center that dopant ion concentration is low is α _A0, gain medium peak value center absorption coefficient that dopant ion concentration is high is α _B0The pairing pumping threshold of the gain medium that dopant ion concentration is different is identical, if the absorption length of gain medium is identical, then the absorption coefficient of the gain media of laser threshold correspondence is α ₀, its corresponding curve a pumping wavelength is λ a ₁～λ a ₂, corresponding curve b pumping wavelength is λ b ₁～λ b ₂, obviously dopant ion concentration is high more; The effective pump-wavelength range of pump light is big more, and its pumping wavelength is λ ₁～λ ₂Scope, obviously dopant ion concentration is high more, and the absorption coefficient of gain medium is also big more.

But the dopant ion concentration of gain medium is high more, and absorption coefficient is big more, and the thermal focal length that brings is just short more, is not suitable for the pump laser of pumping higher-wattage more.The pumping point position of gain medium can change along with the change of pump light wavelength simultaneously, the pump laser incompatibility changes the pumping point with the pump optical wavelength in actual the use, promptly can only select a pumping point, therefore pumping wavelength is when effectively the absorption band wide region is worked, serious mismatch is put in pumping, can not fine work, even mismatch fully; And dopant ion concentration is not suitable for too high, otherwise all there is the fluorescent quenching effect in general gain medium.So high-dopant concentration and the low gain medium of doping content all can not work alone in the broad pump-wavelength range.

Summary of the invention

The object of the invention provides gain medium that a kind of employing oozes assorted concentration and other optical elements formation, is suitable for the semiconductor pumped laser in the work of broad pump-wavelength range.

The utility model adopts following structure: semiconductor pump laser comprises semiconductor laser pumping source, optical coupling system and laser cavity, chamber sheet, gain medium and the optical element except that gain medium before and after laser cavity comprises, wherein gain medium is made up of two or two above dopant ion concentration differences or the different gain medium of absorption coefficient, and different gain mediums is pressed dopant ion concentration or the ascending arrangement of absorption coefficient along the pump light incident direction.

The polarization direction of described different gain medium absorbs isotropism.

During the polarization direction absorption anisotropy of described different gain medium, the optical axis direction free adjustment of different gain mediums is placed, form the pump light polarization direction and absorb the front end that weak gain medium is placed on the pump light incident direction, after the pump light polarization direction strong gain medium of absorption is placed on.

Described laser cavity is separate type laser cavity or micro-piece type laser cavity.

The present invention adopts said structure, pump light enters when oozing the gain medium that heteroion concentration difference or the different gain medium of absorption coefficient combine, the advanced person is infiltrated the gain medium that heteroion concentration is low or absorption coefficient is low, enter the gain medium that oozes heteroion concentration height or high absorption coefficient thereafter, utilize the low gain medium absorption portion pump light of dopant ion concentration, pump light another part sees through low-doped gain medium and is doped the higher gain medium pump absorption of ion concentration, reduce the thermal lensing effect of the high gain medium of dopant ion concentration, can strengthen simultaneously the absorption of pump light, thereby obtain to be suitable for the semiconductor pumped laser of broad pump-wavelength range work, promptly obtain the semiconductor pumped laser of wide temperature work.

Description of drawings

Now in conjunction with the accompanying drawings the present invention is further elaborated:

Fig. 1 is the structural representation of existing semiconductor pump laser;

Fig. 2 is the gain medium absorption coefficient curve chart of different dopant ion concentration;

Fig. 3 is the structural representation of semiconductor pump laser of the present invention.

Embodiment

See also shown in Figure 3ly, the present invention includes semiconductor laser pumping source 1, optical coupling system 2 and laser cavity 3,

chamber sheet

33,36, gain medium 34 and the optical element except that gain medium 35 before and after laser cavity 3 comprises are as frequency-doubling crystal etc.Wherein gain medium 34 is by two or two above dopant ion concentration differences or the different gain medium 341,342 of absorption coefficient ... form, when different gain medium 341,342 ... press dopant ion concentration or the ascending arrangement of absorption coefficient along the pump light incident direction, different gain mediums 341,342 ... be that each lattice direction absorbs identical gain media, the gain medium 341 that concentration is lower is placed on the front end of pump light incident direction, after the gain medium 342 that concentration is bigger is placed on; When the different gain medium 341,342 of absorption coefficient ... the polarization direction absorption anisotropy time, different gain mediums 341,342 ... the optical axis direction unanimity, the gain medium 341 that concentration is lower is placed on the front end of pump light incident direction, after the gain medium 342 that concentration is bigger is placed on; When different gain medium 341,342 ... the polarization direction absorption anisotropy time, as the birefringece crystal gain medium, during the polarization direction absorption anisotropy of different gain mediums, different gain mediums 341,342 ... optical axis direction can free adjustment place, form the pump light polarization direction and absorb the front end that weak gain medium 341 is placed on the pump light incident direction, after the pump light polarization direction strong gain medium 342 of absorption is placed on.

Because the same concentration both direction of birefringece crystal gain medium absorption coefficient differs bigger sometimes, the present invention can adopt the big polarization direction of concentration to absorb weak different gain medium 341 and be placed on gain medium 3 front ends, in other words to birefringece crystal absorbing crystal gain medium based on concentration and two combined factors gained of polarization absorption direction absorption coefficient, the different gain medium 341 that absorption coefficient is little is placed on pump light front end absorptive pumping light center band of light, and the big different gain medium 342 of absorption coefficient is as pump end plain edge edge absorbing medium.

Above-mentioned laser cavity 3 is separate type laser cavity or micro-piece type laser cavity.

When pump light wavelength during at absworption peak center near zone, at first enter the low gain medium of dopant ion concentration 341, because the low gain medium 341 of this region doping ion concentration will effectively absorb pump light, promptly absorb most pump energies, seldom pump light sees through the low gain medium 341 of ion doping concentration and enters the high gain medium of ion doping concentration 342, so the thermal lens appropriateness; When pump light wavelength during away from the absworption peak central area, because the gain medium 341 that dopant ion concentration is low is less to the absorption of this wave band, most of pump light enters the high gain medium of dopant ion concentration 342, the high gain medium 342 of dopant ion concentration this moment is because pump light departs from absorbent core, it is more suitable that its absorption coefficient becomes, absorb simultaneously from the low gain medium 341 remaining pump lights of dopant ion concentration, thermal lens is also moderate.So suitably regulate the concentration and the thickness of the gain medium of different dopant ion concentration, can form broad pumping wavelength zone thermal lens parameter and change suitable semiconductor pump laser, thereby obtain the semiconductor pump laser of wide temperature work.

Claims

1. semiconductor pump laser, comprise the semiconductor laser pumping source, optical coupling system and laser cavity, chamber sheet before and after laser cavity comprises, gain medium, and the optical element except that gain medium, it is characterized in that: gain medium is made up of two or two above dopant ion concentration differences or the different gain medium of absorption coefficient, different gain mediums is pressed dopant ion concentration or the ascending arrangement of absorption coefficient along the pump light incident direction, its different gain medium is that each lattice direction absorbs identical gain media, the gain medium that concentration is lower is placed on the front end of pump light incident direction, after the gain medium that concentration is bigger is placed on.

2. semiconductor pump laser, comprise the semiconductor laser pumping source, optical coupling system and laser cavity, chamber sheet before and after laser cavity comprises, gain medium, and the optical element except that gain medium, it is characterized in that: gain medium is made up of two or two above dopant ion concentration differences or the different gain medium of absorption coefficient, different gain mediums is pressed dopant ion concentration or the ascending arrangement of absorption coefficient along the pump light incident direction, during the polarization direction absorption anisotropy of the gain medium that its absorption coefficient is different, the optical axis direction unanimity of different gain mediums, the gain medium that concentration is lower is placed on the front end of pump light incident direction, after the gain medium that concentration is bigger is placed on.

3. semiconductor pump laser, comprise the semiconductor laser pumping source, optical coupling system and laser cavity, chamber sheet before and after laser cavity comprises, gain medium, and the optical element except that gain medium, it is characterized in that: gain medium is made up of two or two above dopant ion concentration differences or the different gain medium of absorption coefficient, different gain mediums is pressed dopant ion concentration or the ascending arrangement of absorption coefficient along the pump light incident direction, during the polarization direction absorption anisotropy of the gain medium that they are different, the optical axis direction free adjustment of different gain mediums is placed, form the pump light polarization direction and absorb the front end that weak gain medium is placed on the pump light incident direction, after the pump light polarization direction strong gain medium of absorption is placed on.

4. according to claim 1,2 or 3 described a kind of semiconductor pump lasers, it is characterized in that: its laser cavity is separate type laser cavity or micro-piece type laser cavity.