A new process method is proposed to improve the light output power of GaAs vertical cavity surface-emitting lasers （VCSELs）. The VCSELs with open-annulus-distributed holes have a light output power 1.34 times higher...A new process method is proposed to improve the light output power of GaAs vertical cavity surface-emitting lasers （VCSELs）. The VCSELs with open-annulus-distributed holes have a light output power 1.34 times higher than those with ring trenches. The 14μm-aperture devices have a light output power higher than 10mW and have a maximum of 12.48mW at 29.6mA. In addition,open-annulus-distributed holes offer bridges for current injection,so the connecting Ti-Au metal between the ohmic contact and bonding pad does not have to cross the ring trench, and it therefore would not cause the connecting metal to be broken. These VCSELs also show high-temperature operation capabilities,and they have a maximum output power of 8mW even at an operation temperature of up to 60℃.展开更多
To achieve high optical power as well as low vertical divergence angle,a new kind of optim ized large opti- cal cavity (L OC) structure is applied to a ridge waveguide 980 nm In Ga As/ Ga As/ Al Ga As m ulti- quantum...To achieve high optical power as well as low vertical divergence angle,a new kind of optim ized large opti- cal cavity (L OC) structure is applied to a ridge waveguide 980 nm In Ga As/ Ga As/ Al Ga As m ulti- quantum well laser.The optical power density in the waveguide is successfully reduced.The maxim um output power is more than 40 0 m W with a slope efficiency of 0 .89W/ A and the far- field vertical divergence angle is lowered to 2 3°.展开更多
The tunable BIG RW distributed Bragg reflector lasers with two different coupling coefficient gratings are proposed and fabricated.The threshold current of the laser is 38mA and the output power is more than 8mW.The ...The tunable BIG RW distributed Bragg reflector lasers with two different coupling coefficient gratings are proposed and fabricated.The threshold current of the laser is 38mA and the output power is more than 8mW.The tunable range of the laser is 3 2nm and the side mode suppression ratio is more than 30dB.The variation of the output power within the tunable wavelength range is less than 0 3dB.展开更多
High slope efficiency and high power selected oxide-confined 850nm VCSELs grown by MOCVD are reported.The slope efficiency and the threshold current respectively are 0 82mW/mA and 2 59mA with a 9μm diameter oxidati...High slope efficiency and high power selected oxide-confined 850nm VCSELs grown by MOCVD are reported.The slope efficiency and the threshold current respectively are 0 82mW/mA and 2 59mA with a 9μm diameter oxidation aperture at 25℃.The maximum power of 16mW is obtained at 23mA current bias.The minimum threshold current can be as low as 570μA with a 5μm diameter oxidation aperture at 25℃.The maximum saturated power is 5 5mW.展开更多
The two-section tunable ridge waveguide distribu ted Bragg reflector (DBR) laser fabricated by the selective intermixing of an InGaAsP-InGaAsP quantum well structure is presented.The threshold current of the laser is ...The two-section tunable ridge waveguide distribu ted Bragg reflector (DBR) laser fabricated by the selective intermixing of an InGaAsP-InGaAsP quantum well structure is presented.The threshold current of the laser is 51mA.The tunable range of the laser is 4.6nm,and the side mode suppress ion ratio (SMSR) is 40dB.展开更多
The beams of 980nm high-power LDs are analyzed, and the reasons that aspect ratio of LD beams is high are explained. It is certified by the test that cylindrical lens can efficiently compress the perpendicular diverge...The beams of 980nm high-power LDs are analyzed, and the reasons that aspect ratio of LD beams is high are explained. It is certified by the test that cylindrical lens can efficiently compress the perpendicular divergence angle of the beam. Some typical and popular lensed fibers were compared and analyzed according to coupling characteristics. The factors which affect the coupling efficiency and tolerance of the wedged-shaped GRIN tipped lensed fiber are pointed out, and some methods to reduce the coupling loss of the lensed fibers are proposed finally.展开更多
In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm ...In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm laser rotary encoder is mainly introduced, as well as the choice of principal devices.展开更多
The wavelength tuning ranges of a grating external-cavity laser diode (ECLD) have been studied by the equivalent cavity method. The maximum tuning range (MTR) and the continuous tuning range (CTR), which are related t...The wavelength tuning ranges of a grating external-cavity laser diode (ECLD) have been studied by the equivalent cavity method. The maximum tuning range (MTR) and the continuous tuning range (CTR), which are related to the maximum and the minimum threshold carrier densities, are deduced from the threshold condition. We define a ratio of the CTR to the MTR. This ratio is only determined by the reflectivities of the external and internal facets of the ECLD. The analysis shows that there is an appropriate combination of the external and internal-cavity reflectivities to obtain a given CTR in the design of an ECLD.展开更多
To implement high quality tunneling injection quantum dot lasers, effects of primary factors on performance of the tunneling injection quantum dot lasers were investigated. The considered factors were tunneling probab...To implement high quality tunneling injection quantum dot lasers, effects of primary factors on performance of the tunneling injection quantum dot lasers were investigated. The considered factors were tunneling probability, tun- neling time and carriers thermal escape time from the quantum well. The calculation results show that with increas- ing of the ground-state energy level in quantum well, the tunneling probability increases and the tunneling time decreases, while the thermal escape time decreases because the ground-state energy level is shallower. Longitudinal optical phonon-assisted tunneling can be an effective method to solve the problem that both the tunneling time and the thermal escape time decrease simultaneously with the ground-state energy level increasing in quantum well.展开更多
We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted ...We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted multiple stripe conventional single quantum well separate confinement heterostructure(SQW-SCH) GaAlAs diode laser array has been realized.These devices exhibit the lateral far-field radiation pattern of a phase-locked array of gain-guided semiconductor injection laser array.The twenty stripe laser array has a lateral far-field beam divergence full width at half maximum(FWHM) of less than 3°,and three twenty stripe laser array has a beam divergence in the plane of the junction of about 9°.展开更多
文摘A new process method is proposed to improve the light output power of GaAs vertical cavity surface-emitting lasers （VCSELs）. The VCSELs with open-annulus-distributed holes have a light output power 1.34 times higher than those with ring trenches. The 14μm-aperture devices have a light output power higher than 10mW and have a maximum of 12.48mW at 29.6mA. In addition,open-annulus-distributed holes offer bridges for current injection,so the connecting Ti-Au metal between the ohmic contact and bonding pad does not have to cross the ring trench, and it therefore would not cause the connecting metal to be broken. These VCSELs also show high-temperature operation capabilities,and they have a maximum output power of 8mW even at an operation temperature of up to 60℃.
文摘To achieve high optical power as well as low vertical divergence angle,a new kind of optim ized large opti- cal cavity (L OC) structure is applied to a ridge waveguide 980 nm In Ga As/ Ga As/ Al Ga As m ulti- quantum well laser.The optical power density in the waveguide is successfully reduced.The maxim um output power is more than 40 0 m W with a slope efficiency of 0 .89W/ A and the far- field vertical divergence angle is lowered to 2 3°.
文摘The tunable BIG RW distributed Bragg reflector lasers with two different coupling coefficient gratings are proposed and fabricated.The threshold current of the laser is 38mA and the output power is more than 8mW.The tunable range of the laser is 3 2nm and the side mode suppression ratio is more than 30dB.The variation of the output power within the tunable wavelength range is less than 0 3dB.
文摘High slope efficiency and high power selected oxide-confined 850nm VCSELs grown by MOCVD are reported.The slope efficiency and the threshold current respectively are 0 82mW/mA and 2 59mA with a 9μm diameter oxidation aperture at 25℃.The maximum power of 16mW is obtained at 23mA current bias.The minimum threshold current can be as low as 570μA with a 5μm diameter oxidation aperture at 25℃.The maximum saturated power is 5 5mW.
文摘The two-section tunable ridge waveguide distribu ted Bragg reflector (DBR) laser fabricated by the selective intermixing of an InGaAsP-InGaAsP quantum well structure is presented.The threshold current of the laser is 51mA.The tunable range of the laser is 4.6nm,and the side mode suppress ion ratio (SMSR) is 40dB.
文摘The beams of 980nm high-power LDs are analyzed, and the reasons that aspect ratio of LD beams is high are explained. It is certified by the test that cylindrical lens can efficiently compress the perpendicular divergence angle of the beam. Some typical and popular lensed fibers were compared and analyzed according to coupling characteristics. The factors which affect the coupling efficiency and tolerance of the wedged-shaped GRIN tipped lensed fiber are pointed out, and some methods to reduce the coupling loss of the lensed fibers are proposed finally.
文摘In this paper, the operation principle of laser rotary encoders is expounded and the optical quadruple frequency technology used in laser rotary encoders is explained, and the design idea of optical system in φ66 mm laser rotary encoder is mainly introduced, as well as the choice of principal devices.
基金The Foundation of National Railways Ministry , National Studying
文摘The wavelength tuning ranges of a grating external-cavity laser diode (ECLD) have been studied by the equivalent cavity method. The maximum tuning range (MTR) and the continuous tuning range (CTR), which are related to the maximum and the minimum threshold carrier densities, are deduced from the threshold condition. We define a ratio of the CTR to the MTR. This ratio is only determined by the reflectivities of the external and internal facets of the ECLD. The analysis shows that there is an appropriate combination of the external and internal-cavity reflectivities to obtain a given CTR in the design of an ECLD.
基金the National Natural Science Foundationof China (Grant No. 60476042) and Tianjin City Research Founda-tion for Key Basic Research, China (Grant No. 06YFJZJC01100)
文摘To implement high quality tunneling injection quantum dot lasers, effects of primary factors on performance of the tunneling injection quantum dot lasers were investigated. The considered factors were tunneling probability, tun- neling time and carriers thermal escape time from the quantum well. The calculation results show that with increas- ing of the ground-state energy level in quantum well, the tunneling probability increases and the tunneling time decreases, while the thermal escape time decreases because the ground-state energy level is shallower. Longitudinal optical phonon-assisted tunneling can be an effective method to solve the problem that both the tunneling time and the thermal escape time decrease simultaneously with the ground-state energy level increasing in quantum well.
文摘We report one thick layer of hard-baked photoresist mask.The laser array stripe pattern was defined by standard wet lithography.With this mask, a 10 W QCW(quasi-continuous wave) operation of a narrow proton implanted multiple stripe conventional single quantum well separate confinement heterostructure(SQW-SCH) GaAlAs diode laser array has been realized.These devices exhibit the lateral far-field radiation pattern of a phase-locked array of gain-guided semiconductor injection laser array.The twenty stripe laser array has a lateral far-field beam divergence full width at half maximum(FWHM) of less than 3°,and three twenty stripe laser array has a beam divergence in the plane of the junction of about 9°.
