We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the thre...We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.展开更多
In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode （LD）, we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by met...In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode （LD）, we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by metal organic chemical vapor deposition （MOCVD）. For the devices with 100-ttm-wide stripe and 1000-/zm-long cavity under continuous-wave （CW） operation condition, the typical threshold current is 190 mA, the slope efficiency is 1.31 W/A, the wall-plug efficiency reaches 63%, and the maximum output power reaches higher than 7 W. And the internal absorption value decreases to 1.5 cm^-1.展开更多
Asymmetric broad-waveguide separate-confinement heterostructure（BW-SCH） quantum well（QW） laser diode emitting at 808 nm is analyzed and designed theoretically.The dependence of the optical field distribution, vert...Asymmetric broad-waveguide separate-confinement heterostructure（BW-SCH） quantum well（QW） laser diode emitting at 808 nm is analyzed and designed theoretically.The dependence of the optical field distribution, vertical far-field angle,and internal loss on different thicknesses of the upper waveguide layer is calculated and analyzed.Calculated results show that when the thicknesses of the lower and upper waveguide layers are 0.45 and 0.3μm,respectively,for the devices with 100-μm-wide stripe and 1000-μm-long cavity,an output power of 7.6 W at 8 A,a vertical far-field angle of 37°,a slope efficiency of 1.32 W/A, and a threshold current of 189 mA can be obtained.展开更多
Ga In As P layers and Ga As P/（Al） Ga In P laser diodes（LDs） have been grown on Ga As substrates by metalorganic chemical vapor deposition. The Ga In As P layer, which is lattice matched to Ga As, has an intermedi...Ga In As P layers and Ga As P/（Al） Ga In P laser diodes（LDs） have been grown on Ga As substrates by metalorganic chemical vapor deposition. The Ga In As P layer, which is lattice matched to Ga As, has an intermediate band gap between Ga0.5In0.5P and Ga As. The Ga In P/Ga As heterojunction spikes, especially in the valence band,can be suppressed by introducing this thin Ga In As P layer into the heterostructure interface. The 808 nm Ga As P/（Al）Ga In P LDs with Ga In As P intermediate layer show a reduced operating voltage compared to the conventional LDs with abrupt Ga In P/Ga As interface due to the enhanced hole injection. As a result, the power conversion efficiency is improved from 52% to 60% at 350 m W output power. At high current injection, the LD with Ga In As P intermediate layer has higher light power owing to the decreased joule heating.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB632801 and 2013CB632803the National Natural Science Foundation of China under Grant Nos 61435014,61306058 and 61274094the Beijing Natural Science Foundation under Grant No 4144086
文摘We report on the room-temperature cascade laser （QCL） at λ -4.7μm. cw operation of a surface grating Both grating design and material distributed feedback （DFB） quantum optimization are used to decrease the threshold current density and to increase the output power. For a high-reflectivity-coated 13-μm-wide and 4- mm-long laser, high wall-plug efficiency of 6% is obtained at 20℃ from a single facet producing over I W of ew output power. The threshold current density of DFB QCL is as low as 1.13kA/cm^2 at 10℃ and 1.34kA/cm2 at 30℃ in cw mode. Stable single-mode emission with a side-mode suppression ratio of about 30 dB is observed in tile working temperature range of 20-50℃.
基金supported by the National Natural Science Foundation of China (No.50472068)the Program for New Century Excellent Talents in University
文摘In order to improve the characteristics of the general broad-waveguide 808-nm semiconductor laser diode （LD）, we design a new type quantum well LD with an asymmetric cladding structure. The structure is grown by metal organic chemical vapor deposition （MOCVD）. For the devices with 100-ttm-wide stripe and 1000-/zm-long cavity under continuous-wave （CW） operation condition, the typical threshold current is 190 mA, the slope efficiency is 1.31 W/A, the wall-plug efficiency reaches 63%, and the maximum output power reaches higher than 7 W. And the internal absorption value decreases to 1.5 cm^-1.
基金supported by the National Natural Science Foundation of China(No.50472068)the Program for New Century Excellent Talents in University.
文摘Asymmetric broad-waveguide separate-confinement heterostructure（BW-SCH） quantum well（QW） laser diode emitting at 808 nm is analyzed and designed theoretically.The dependence of the optical field distribution, vertical far-field angle,and internal loss on different thicknesses of the upper waveguide layer is calculated and analyzed.Calculated results show that when the thicknesses of the lower and upper waveguide layers are 0.45 and 0.3μm,respectively,for the devices with 100-μm-wide stripe and 1000-μm-long cavity,an output power of 7.6 W at 8 A,a vertical far-field angle of 37°,a slope efficiency of 1.32 W/A, and a threshold current of 189 mA can be obtained.
基金Project supported by the National Key Basic Research Program of China(No.2013CB632801)
文摘Ga In As P layers and Ga As P/（Al） Ga In P laser diodes（LDs） have been grown on Ga As substrates by metalorganic chemical vapor deposition. The Ga In As P layer, which is lattice matched to Ga As, has an intermediate band gap between Ga0.5In0.5P and Ga As. The Ga In P/Ga As heterojunction spikes, especially in the valence band,can be suppressed by introducing this thin Ga In As P layer into the heterostructure interface. The 808 nm Ga As P/（Al）Ga In P LDs with Ga In As P intermediate layer show a reduced operating voltage compared to the conventional LDs with abrupt Ga In P/Ga As interface due to the enhanced hole injection. As a result, the power conversion efficiency is improved from 52% to 60% at 350 m W output power. At high current injection, the LD with Ga In As P intermediate layer has higher light power owing to the decreased joule heating.
