An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase curr...An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.展开更多
The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors （DBR） is studied by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Some voids distribute along t...The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors （DBR） is studied by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Some voids distribute along the oxide/GaAs interfaces due to the stress induced by the wet oxidation of the AlGaAs layers. These voids decrease the shrinkage of the Al2O3 layers to 8% instead of the theoretical 20% when compared to the unoxidized AlGaAs layers. With the extension of oxidation time, the reactants are more completely transported to the front interface and the products are more completely transported out along the porous interfaces. As a result,the oxide quality is better.展开更多
We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase sec...We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.展开更多
We investigate metallic microdisk-size dependence of quantum dot （QD） spontaneous emission rate and micro- antenna directional emission effect for the hybrid metM-distributed Bragg reflector structures based on a pa...We investigate metallic microdisk-size dependence of quantum dot （QD） spontaneous emission rate and micro- antenna directional emission effect for the hybrid metM-distributed Bragg reflector structures based on a particular single QD emission. It is found that the measured photolumineseence （PL） intensity is very sensitive to the size of metMlic disk, showing an enhancement factor of 11 when the optimal disk diameter is 2μm and the numerical aperture of microscope objective NA=0.5. It is found that for large metal disks, the Purcell effect is dominant for enhanced PL intensity, whereas for small size disks the main contribution comes from plasmon scattering at the disk edge within the light cone collected by the microscope objective.展开更多
The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers o...The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers of both the p-and n-DBR mirrors are analysed by combining the thermionic emission model and the finite difference method.In the meantime,the intrinsic resistance of the DBR material system is calculated to make a comparison with the junction resistance.The minimal values of series resistances of the graded p-and n-type DBR mirrors and the lateral temperature-dependent resistance variation are calculated and discussed.The result indicates the potential to optimize the design of the DBR reflectors of the 980-nm VCSELs.展开更多
A 1040 nm tapered laser with tapered distributed Bragg reflector(DBR) grating is designed and fabricated. By designing the grating with tapered layout, the tapered DBR grating exhibits the scattering effect on side ba...A 1040 nm tapered laser with tapered distributed Bragg reflector(DBR) grating is designed and fabricated. By designing the grating with tapered layout, the tapered DBR grating exhibits the scattering effect on side backward-traveling waves, thus achieving additional suppression of parasitic oscillation. Under the suppression of parasitic oscillation, the spatial and spectral characteristics of the tapered laser are improved. The experimental results show that a near-Gaussian far-field distribution and a kink-free P–I characteristics are achieved, and a single peak emission with a wavelength of1046.84 nm and a linewidth of 56 pm is obtained.展开更多
Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected...Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected high quality epitaxial DBR structure was verified.In the X-ray double-crystal rocking curves of DBR the zeroth-order peak,the first and second order satellite peaks were measured.Splitting of diffraction peak appeared in the rocking curves was analyzed.The effects of introduced deep energy levels on the structural perfection and optical properties were discussed.展开更多
A new design for an all optical flip flop is introduced. It is based on a nonlinear Distributed Bragg Reflector (DBR) semiconductor laser structure. The device does not require a holding beam. An optical gain medium c...A new design for an all optical flip flop is introduced. It is based on a nonlinear Distributed Bragg Reflector (DBR) semiconductor laser structure. The device does not require a holding beam. An optical gain medium confined between 2 Bragg reflectors forms the device. One of the Bragg reflectors is detuned from the other by making its average refractive index slightly higher, and it has a negative nonlinear coefficient that is due to direct absorption at Urbach tail. At low light intensity in the structure, the detuned Bragg reflector does not provide optical feedback to start a laser mode. An optical pulse injected to the structure reduces the detuning of the nonlinear Bragg reflector and a laser mode builds up. The device is reset by detuning the second Bragg reflector optically by an optical pulse that generates electron-hole pairs by direct absorption. A mathematical model of the device is introduced. The model is solved numerically in time domain using a general purpose graphics processing unit (GPGPU) to increase accuracy and to reduce the computation time. The switching dynamics of the device are in nanosecond time scale. The device could be used for all optical data packet switching/routing.展开更多
The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calcu-lated using the 2D finite difference time domain(FDTD)algorithm and the scattering matrix method(SMM)....The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calcu-lated using the 2D finite difference time domain(FDTD)algorithm and the scattering matrix method(SMM).The periods and etch depth of the grating parameters have been optimized.A board area laser diode(BA-LD)with high-order diffraction grat-ings has been designed and fabricated.At output powers up to 10.5 W,the measured spectral width of full width at half maxi-mum(FWHM)is less than 0.5 nm.The results demonstrate that the designed high-order surface gratings can effectively nar-row the spectral width of multimode semiconductor lasers at high output power.展开更多
The linewidths of InGaAs-GaAs-AlGaAs DBR lasers with varied DBR dimensional parameters are measured and analyzed. These lasers were built with different DBR grating lengths and depths in order to explore the effect of...The linewidths of InGaAs-GaAs-AlGaAs DBR lasers with varied DBR dimensional parameters are measured and analyzed. These lasers were built with different DBR grating lengths and depths in order to explore the effect of the size of the DBR on its coupling coefficient and reflectivity,and hence on the linewidth of the laser diodes. The linewidths were measured by employing a self heterodyne linewidth measurement system. The experimental and calculated data for DBR reflectivity and spectral linewidth are given. The relationship between these data and the dimensions of the DBR is analyzed. Based on this analysis,the effect of the DBR geometry on the linewidth of the lasers is explored. The results give useful information related to the design and fabrication of such DBR lasers.展开更多
The 3-section SG-DBR tunable laser is fabricate d using an ion implantation quantum-well intermixing process.The over 30nm discontinuous tuning range is achieved with the SMRS greater than 30dB.
文摘An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.
文摘The wet oxidation of AlGaAs with high Al content in a distributed Bragg reflectors （DBR） is studied by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Some voids distribute along the oxide/GaAs interfaces due to the stress induced by the wet oxidation of the AlGaAs layers. These voids decrease the shrinkage of the Al2O3 layers to 8% instead of the theoretical 20% when compared to the unoxidized AlGaAs layers. With the extension of oxidation time, the reactants are more completely transported to the front interface and the products are more completely transported out along the porous interfaces. As a result,the oxide quality is better.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60736036 and 61021003)the National Basic Research Program of China (Grant No. 2011CB301702)
文摘We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.
基金Supported by the National Key Basic Research Program of China under Grant No 2013CB922304the National Natural Science Foundation of China under Grant Nos 11474275 and 11464034
文摘We investigate metallic microdisk-size dependence of quantum dot （QD） spontaneous emission rate and micro- antenna directional emission effect for the hybrid metM-distributed Bragg reflector structures based on a particular single QD emission. It is found that the measured photolumineseence （PL） intensity is very sensitive to the size of metMlic disk, showing an enhancement factor of 11 when the optimal disk diameter is 2μm and the numerical aperture of microscope objective NA=0.5. It is found that for large metal disks, the Purcell effect is dominant for enhanced PL intensity, whereas for small size disks the main contribution comes from plasmon scattering at the disk edge within the light cone collected by the microscope objective.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974012)
文摘The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers of both the p-and n-DBR mirrors are analysed by combining the thermionic emission model and the finite difference method.In the meantime,the intrinsic resistance of the DBR material system is calculated to make a comparison with the junction resistance.The minimal values of series resistances of the graded p-and n-type DBR mirrors and the lateral temperature-dependent resistance variation are calculated and discussed.The result indicates the potential to optimize the design of the DBR reflectors of the 980-nm VCSELs.
基金Project supported by Jilin Science and Technology Development Plan,China(Grant Nos.20210201030GX and 20190302052GX)。
文摘A 1040 nm tapered laser with tapered distributed Bragg reflector(DBR) grating is designed and fabricated. By designing the grating with tapered layout, the tapered DBR grating exhibits the scattering effect on side backward-traveling waves, thus achieving additional suppression of parasitic oscillation. Under the suppression of parasitic oscillation, the spatial and spectral characteristics of the tapered laser are improved. The experimental results show that a near-Gaussian far-field distribution and a kink-free P–I characteristics are achieved, and a single peak emission with a wavelength of1046.84 nm and a linewidth of 56 pm is obtained.
文摘Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected high quality epitaxial DBR structure was verified.In the X-ray double-crystal rocking curves of DBR the zeroth-order peak,the first and second order satellite peaks were measured.Splitting of diffraction peak appeared in the rocking curves was analyzed.The effects of introduced deep energy levels on the structural perfection and optical properties were discussed.
文摘A new design for an all optical flip flop is introduced. It is based on a nonlinear Distributed Bragg Reflector (DBR) semiconductor laser structure. The device does not require a holding beam. An optical gain medium confined between 2 Bragg reflectors forms the device. One of the Bragg reflectors is detuned from the other by making its average refractive index slightly higher, and it has a negative nonlinear coefficient that is due to direct absorption at Urbach tail. At low light intensity in the structure, the detuned Bragg reflector does not provide optical feedback to start a laser mode. An optical pulse injected to the structure reduces the detuning of the nonlinear Bragg reflector and a laser mode builds up. The device is reset by detuning the second Bragg reflector optically by an optical pulse that generates electron-hole pairs by direct absorption. A mathematical model of the device is introduced. The model is solved numerically in time domain using a general purpose graphics processing unit (GPGPU) to increase accuracy and to reduce the computation time. The switching dynamics of the device are in nanosecond time scale. The device could be used for all optical data packet switching/routing.
基金supported by the National Key R&D Program of China,No.2022YFB4601201.
文摘The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calcu-lated using the 2D finite difference time domain(FDTD)algorithm and the scattering matrix method(SMM).The periods and etch depth of the grating parameters have been optimized.A board area laser diode(BA-LD)with high-order diffraction grat-ings has been designed and fabricated.At output powers up to 10.5 W,the measured spectral width of full width at half maxi-mum(FWHM)is less than 0.5 nm.The results demonstrate that the designed high-order surface gratings can effectively nar-row the spectral width of multimode semiconductor lasers at high output power.
文摘The linewidths of InGaAs-GaAs-AlGaAs DBR lasers with varied DBR dimensional parameters are measured and analyzed. These lasers were built with different DBR grating lengths and depths in order to explore the effect of the size of the DBR on its coupling coefficient and reflectivity,and hence on the linewidth of the laser diodes. The linewidths were measured by employing a self heterodyne linewidth measurement system. The experimental and calculated data for DBR reflectivity and spectral linewidth are given. The relationship between these data and the dimensions of the DBR is analyzed. Based on this analysis,the effect of the DBR geometry on the linewidth of the lasers is explored. The results give useful information related to the design and fabrication of such DBR lasers.
文摘The 3-section SG-DBR tunable laser is fabricate d using an ion implantation quantum-well intermixing process.The over 30nm discontinuous tuning range is achieved with the SMRS greater than 30dB.
