We investigate a strain compensation method for the growth of complex interband cascade laser structures. For thick In As/Al Sb superlattice clad layers, the sublayer thicknesses were adjusted so that the tensile stra...We investigate a strain compensation method for the growth of complex interband cascade laser structures. For thick In As/Al Sb superlattice clad layers, the sublayer thicknesses were adjusted so that the tensile strain energy in the In As sublayer was equal to the compressive strain energy in the Al Sb sublayer. For the four-constituent active region, as the compressive strain in the Ga0.65In0.35Sb alloy layer was large, a tensile strain was incorporated in the chirped In As/Al Sb superlattice region for strain compensation to the Ga0.65In0.35Sb alloy. A laser structure of thickness 6 μm was grown on the Ga Sb substrate by molecular beam epitaxy. The wafer exhibited good surface morphology and high crystalline quality.展开更多
We demonstrated an electrically pumped InP-based microcavity laser operating in continuous-wave mode.The active region is designed with antimony surfactants to enhance the gain at 2 μm,and a selective electrical isol...We demonstrated an electrically pumped InP-based microcavity laser operating in continuous-wave mode.The active region is designed with antimony surfactants to enhance the gain at 2 μm,and a selective electrical isolation scheme is used to secure continuous-wave operation for the microcavity laser at room temperature.The lasers were fabricated as a notched elliptical resonator,resulting in a highly unidirectional far-field profile with an in-plane beam divergence of less than 2°.Single-mode emission was obtained over the entire dynamic range,and the laser frequencies were tuned linearly with the pumping current.Overall,these directional lasers pave the way for portable and highly integrated on-chip sensing applications.展开更多
We report on the design and fabrication of a dual-wavelength switchable quantum cascade laser(QCL)by optimizing thedesign of a homogeneous active region and combining superposed distributed feedback gratings.Coaxial,s...We report on the design and fabrication of a dual-wavelength switchable quantum cascade laser(QCL)by optimizing thedesign of a homogeneous active region and combining superposed distributed feedback gratings.Coaxial,single-modeemissions at two different wavelengths were achieved only through adjusting the bias voltage.Room temperature continuous-wave operation with output powers of above 30 mW and 75 mW was realized for single-mode emission at 7.61μmand 7.06μm,respectively.The simplified fabrication process and easy wavelength control of our designed dual-wavelengthQCL make it very attractive for developing miniature multi-species gas sensing systems.展开更多
For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with th...For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with that of an ordinary sampled grating laser with an emission wavelength of approximately 8.6μm,when the periodicities within both the base grating and the sample grating are kept constant.Under this condition,an improvement in the continuous tuning capability of the QCL array is ensured.The ASG structure is fabricated in holographic exposure and optical photolithography,thereby enhancing its flexibility,repeatability,and cost-effectiveness.The wavelength modulation capability of the two channels of the grating is insensitive to the variations in channel size,assuming that the overall waveguide width remains constant.The output wavelength can be tailored freely within a certain range by adjusting the width of the ridge and the material of the cladding layer.展开更多
We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes deliv...We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes delivering ~ 3.2 m W of optical power per mode, making it a valuable tool for dual comb spectroscopy. The homogeneous gain medium, relying on a slightly diagonal bound-to-continuum structure, promises to provide a broad and stable gain for comb operating. Remarkably, the dispersion of this device is measured within 300 fs2/mm to ensure stable comb operation over 90% of the total current range. The comb is observed with a narrow beatnote linewidth around 2 k Hz and has weak dependence on the applied current for stable comb operation.展开更多
<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room t...<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range. </div>展开更多
基金Project supported by the National Key Research and Development Project of China (Grant No. 2018YFB2200500)the National Natural Science Foundation of China (Grant Nos. 61790583, 61835011, 62174158 and 61991431)+1 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No. 2021107)the Key Program of the Chinese Academy of Sciences (Grant No. XDB43000000)。
文摘We investigate a strain compensation method for the growth of complex interband cascade laser structures. For thick In As/Al Sb superlattice clad layers, the sublayer thicknesses were adjusted so that the tensile strain energy in the In As sublayer was equal to the compressive strain energy in the Al Sb sublayer. For the four-constituent active region, as the compressive strain in the Ga0.65In0.35Sb alloy layer was large, a tensile strain was incorporated in the chirped In As/Al Sb superlattice region for strain compensation to the Ga0.65In0.35Sb alloy. A laser structure of thickness 6 μm was grown on the Ga Sb substrate by molecular beam epitaxy. The wafer exhibited good surface morphology and high crystalline quality.
基金supported by the National Basic Research Program of China(No.2021YFB3201900)the National Natural Science Foundation of China(Nos.61991430,61790583,and 61774150)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2021107)。
文摘We demonstrated an electrically pumped InP-based microcavity laser operating in continuous-wave mode.The active region is designed with antimony surfactants to enhance the gain at 2 μm,and a selective electrical isolation scheme is used to secure continuous-wave operation for the microcavity laser at room temperature.The lasers were fabricated as a notched elliptical resonator,resulting in a highly unidirectional far-field profile with an in-plane beam divergence of less than 2°.Single-mode emission was obtained over the entire dynamic range,and the laser frequencies were tuned linearly with the pumping current.Overall,these directional lasers pave the way for portable and highly integrated on-chip sensing applications.
基金supported by the National Natural Science Foundation of China(Nos.61874110,61734006,61991430,61835011,and 62174158)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2021107)Key Program of the Chinese Academy of Sciences(No.XDB43000000).
文摘We report on the design and fabrication of a dual-wavelength switchable quantum cascade laser(QCL)by optimizing thedesign of a homogeneous active region and combining superposed distributed feedback gratings.Coaxial,single-modeemissions at two different wavelengths were achieved only through adjusting the bias voltage.Room temperature continuous-wave operation with output powers of above 30 mW and 75 mW was realized for single-mode emission at 7.61μmand 7.06μm,respectively.The simplified fabrication process and easy wavelength control of our designed dual-wavelengthQCL make it very attractive for developing miniature multi-species gas sensing systems.
基金Project supported by the National Basic Research Program of China (Grant No. 2021YFB3201900)in part by the National Natural Science Foundation of China (Grant Nos. 61991430, 61774146, 61790583,61627822, and 61774150)in part by the Key Projects of the Chinese Academy of Sciences (Grant Nos. 2018147, YJKYYQ20190002, QYZDJ-SSW-JSC027,XDB43000000)
文摘For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with that of an ordinary sampled grating laser with an emission wavelength of approximately 8.6μm,when the periodicities within both the base grating and the sample grating are kept constant.Under this condition,an improvement in the continuous tuning capability of the QCL array is ensured.The ASG structure is fabricated in holographic exposure and optical photolithography,thereby enhancing its flexibility,repeatability,and cost-effectiveness.The wavelength modulation capability of the two channels of the grating is insensitive to the variations in channel size,assuming that the overall waveguide width remains constant.The output wavelength can be tailored freely within a certain range by adjusting the width of the ridge and the material of the cladding layer.
基金supported by the National Natural Science Foundation of China(Grant Nos.61734006,61835011,61991430,and 62174158)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2021107)the Key Program of the Chinese Academy of Sciences(Grant Nos.XDB43000000,YJKYYQ20190002,and QYZDJ-SSW-JSC027)。
文摘We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes delivering ~ 3.2 m W of optical power per mode, making it a valuable tool for dual comb spectroscopy. The homogeneous gain medium, relying on a slightly diagonal bound-to-continuum structure, promises to provide a broad and stable gain for comb operating. Remarkably, the dispersion of this device is measured within 300 fs2/mm to ensure stable comb operation over 90% of the total current range. The comb is observed with a narrow beatnote linewidth around 2 k Hz and has weak dependence on the applied current for stable comb operation.
文摘<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range. </div>
