日前 Diodes 公司（ Diodes Incorporated ）推出两款高效低噪声的3 W 单声道 D 类音频放大器 PAM8013及PAM8015，两款产品都采用了超级微小的 QFN1515-9L 封装，尺寸仅为1.5 mm×1.5 mm ×0.75 mm ，为支持MP3播放器、平板电...日前 Diodes 公司（ Diodes Incorporated ）推出两款高效低噪声的3 W 单声道 D 类音频放大器 PAM8013及PAM8015，两款产品都采用了超级微小的 QFN1515-9L 封装，尺寸仅为1.5 mm×1.5 mm ×0.75 mm ，为支持MP3播放器、平板电脑和智能手机等便携式产品的微型化而特别设计。展开更多
We design an 850 nm tunable vertical-cavity surface-emitting laser(VCSEL)structure using an internal-cavity sub-wavelength grating.The use of such a tuning structure allows for wider wavelength tuning range and more s...We design an 850 nm tunable vertical-cavity surface-emitting laser(VCSEL)structure using an internal-cavity sub-wavelength grating.The use of such a tuning structure allows for wider wavelength tuning range and more stable single-polarization as compared to conventional tunable VCSELs.The features of the internal-cavity grating effect on the wavelength tuning and polarization characteristics of the tunable VCSEL are analyzed.The simulation results show that the largest wavelength tuning range achieves 44.2 nm,and the maximum orthogonal polarization suppression ratio(OPSR)is 33.4 dB(TE-type)and 38.7 dB(TM-type).展开更多
Broad area semiconductor laser(BAL)has poor lateral beam quality due to lateral mode competition,which limits its application as a high-power optical source.In this work,the distributed Bragg reflector laser diode wit...Broad area semiconductor laser(BAL)has poor lateral beam quality due to lateral mode competition,which limits its application as a high-power optical source.In this work,the distributed Bragg reflector laser diode with tapered grating(TDBR-LD)is studied.By changing the lateral width,the tapered grating increases the loss of high-order lateral modes,thus improving the lateral characteristics of the laser diode.The measuring results show that the TDBR-LD can achieve a single-lobe output under 0.9 A.In contrast to the straight distributed Bragg reflector laser diode(SDBR-LD),the lateral far field divergence of TDBR-LD is measured to be 5.23°at 1 A,representing a 17%decline.The linewidth of TDBR-LD is 0.4 nm at 0.2 A,which is reduced by nearly 43%in comparison with that of SDBR-LD.Meanwhile,both of the devices have a maximum output power value of approximate 470 mW.展开更多
The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-base...The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-based amorphous ribbon is prepared by single roller quenching and annealed with Joule heat in a flowing nitro- gen atmosphere. The giant magnetoimpedance effect in solenoid （GMIES） profiles are measured with an HP4294A impedance analyzer. The result shows that the CMIES responds to the WMF sensitively （as high as 1580 %/A.m-1）. The high sensitivity can be obtained in a moderate narrow range of annealing current density （30-34 A/mm2） and closely depends on the driven current frequency. The highest sensitivity （1580 %/A.m-1） is obtained when the FeCo- based amorphous ribbon is annealed at 32 A/mm2 for 10 min and then driven with an alterning current （AC） at the frequency of 350 kHz. The highly sensitive GMIES under the WMF may result from the multiple magnetic-anisotropic structure, which is induced by the temperature gradient produced during Joule-heating the ribbon.展开更多
The dispersibility of bio-molecules such as lecithins on the surface of ZnO nanowires are investigated for biosensor applications.Lecithins can be absorbed on an as-synthesized ZnO nanowire surface in the form of sub-...The dispersibility of bio-molecules such as lecithins on the surface of ZnO nanowires are investigated for biosensor applications.Lecithins can be absorbed on an as-synthesized ZnO nanowire surface in the form of sub-micro sized clusters,while scattering well on those annealed under oxygen atmosphere.Wettability analysis reveals that the as-synthesized ZnO nanowires bear a super-hydrophobic surface,which convents to superhydrophilic after oxygen annealing.First-principles calculations indicate that the adsorption energy of ZnO with water is about 0.2 eV at a distance of 2(A) when it is superhydrophilic,suggesting that lecithin can be absorbed on the hydrophilic surface stably at this distance and the bio-affinity can be enhanced under this condition.展开更多
A kind of novel broad-band superluminescent diodes (SLDs) using graded tensile-strained bulk InGaAs is developed. The graded tensile-strained bulk InGaAs is obtained by changing only group-Ⅲ trimethyl-gallium source ...A kind of novel broad-band superluminescent diodes (SLDs) using graded tensile-strained bulk InGaAs is developed. The graded tensile-strained bulk InGaAs is obtained by changing only group-Ⅲ trimethyl-gallium source flow during low-pressure metal organic vapor-phase epitaxy. At the injection current of 200 mA, the fabricated SLDs with such structure demonstrate full-width at half-maximum spectral width of 106 nm and the output light power of 13.6 mW, respectively.展开更多
Parallel optical coherence tomography is demonstrated using a 12-bit scientific-grade charge-coupled device array. A superluminescent diode in combination with a free-space Michelson interferometer was employed to ach...Parallel optical coherence tomography is demonstrated using a 12-bit scientific-grade charge-coupled device array. A superluminescent diode in combination with a free-space Michelson interferometer was employed to achieve 10-μm axial resolution and 1.1-μm transverse resolution on a 902×575 /μm2 field of view. We imaged a test mirror and bovine retinal tissue using a four-step phase shift method.展开更多
Laser drivers are an enabling factor to inertial confinement fusion, because laser diodes must be used instead of flash lamps. We discuss the limitations of laser diode arrays and show what steps the industry is takin...Laser drivers are an enabling factor to inertial confinement fusion, because laser diodes must be used instead of flash lamps. We discuss the limitations of laser diode arrays and show what steps the industry is taking. The pump power requirements of large-scale projects such as LIFE or Hi PER are within reach of semiconductor laser diode assemblies.Pulsed light output powers per laser bars have been around 300 W per bar, as in the Jenoptik 940 nm bars previously used for pumping the Yb:YAG slabs in the Di POLE project. By redesigning the semiconductor laser structures 500 W per bar is now commercially available for 808, 880 and 940 nm pump wavelengths. The construction of one inertial fusion power plant will require an amount of semiconductor laser chips in excess of the current annual production by two orders of magnitude. This adds to the engineering task of improving the device characteristics a challenge to production capacity.While the industry benefits from the recent boost in solid-state lighting that acts as a technology driver, cooperation between manufacturers will be imperative, and to this end we propose standardization efforts.展开更多
文摘日前 Diodes 公司（ Diodes Incorporated ）推出两款高效低噪声的3 W 单声道 D 类音频放大器 PAM8013及PAM8015，两款产品都采用了超级微小的 QFN1515-9L 封装，尺寸仅为1.5 mm×1.5 mm ×0.75 mm ，为支持MP3播放器、平板电脑和智能手机等便携式产品的微型化而特别设计。
基金the Jilin Science and Technology Development Plan,China(Grant Nos.20180519018JH and 20190302052GX)Jilin Education Department“135”Science and Technology,China(Grant No.JJKH20190543KJ)+1 种基金the National Natural Science Foundation of China(Grant No.11474038)the Key Project of Equipment Pre-Research Fund of China(Grant No.61404140103)。
文摘We design an 850 nm tunable vertical-cavity surface-emitting laser(VCSEL)structure using an internal-cavity sub-wavelength grating.The use of such a tuning structure allows for wider wavelength tuning range and more stable single-polarization as compared to conventional tunable VCSELs.The features of the internal-cavity grating effect on the wavelength tuning and polarization characteristics of the tunable VCSEL are analyzed.The simulation results show that the largest wavelength tuning range achieves 44.2 nm,and the maximum orthogonal polarization suppression ratio(OPSR)is 33.4 dB(TE-type)and 38.7 dB(TM-type).
基金Project supported by theScienceand Technology Development Plan of Jilin Province,China(Grant Nos.20210201030GX and 20210201089GX).
文摘Broad area semiconductor laser(BAL)has poor lateral beam quality due to lateral mode competition,which limits its application as a high-power optical source.In this work,the distributed Bragg reflector laser diode with tapered grating(TDBR-LD)is studied.By changing the lateral width,the tapered grating increases the loss of high-order lateral modes,thus improving the lateral characteristics of the laser diode.The measuring results show that the TDBR-LD can achieve a single-lobe output under 0.9 A.In contrast to the straight distributed Bragg reflector laser diode(SDBR-LD),the lateral far field divergence of TDBR-LD is measured to be 5.23°at 1 A,representing a 17%decline.The linewidth of TDBR-LD is 0.4 nm at 0.2 A,which is reduced by nearly 43%in comparison with that of SDBR-LD.Meanwhile,both of the devices have a maximum output power value of approximate 470 mW.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50871104 and 11079029)the Natural Science Foundation of Zhejiang Province,China (Grant Nos. Y4080324 and Y6110246)the Natural Science Foundation of Shanxi Province, China (Grant No. Sj08e101)
文摘The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 （FeCo-based） ribbon under a weak magnetic field （WMF） is presented in this paper. The FeCo-based amorphous ribbon is prepared by single roller quenching and annealed with Joule heat in a flowing nitro- gen atmosphere. The giant magnetoimpedance effect in solenoid （GMIES） profiles are measured with an HP4294A impedance analyzer. The result shows that the CMIES responds to the WMF sensitively （as high as 1580 %/A.m-1）. The high sensitivity can be obtained in a moderate narrow range of annealing current density （30-34 A/mm2） and closely depends on the driven current frequency. The highest sensitivity （1580 %/A.m-1） is obtained when the FeCo- based amorphous ribbon is annealed at 32 A/mm2 for 10 min and then driven with an alterning current （AC） at the frequency of 350 kHz. The highly sensitive GMIES under the WMF may result from the multiple magnetic-anisotropic structure, which is induced by the temperature gradient produced during Joule-heating the ribbon.
基金Supported by the National High Technology Research and Development Program of China under Grant No 2009AA034101the National Natural Science Foundation of China under Grant Nos 50902125 and KYZKJY11106the Postdoctoral Foundation under Grant No O9T1050000.
文摘The dispersibility of bio-molecules such as lecithins on the surface of ZnO nanowires are investigated for biosensor applications.Lecithins can be absorbed on an as-synthesized ZnO nanowire surface in the form of sub-micro sized clusters,while scattering well on those annealed under oxygen atmosphere.Wettability analysis reveals that the as-synthesized ZnO nanowires bear a super-hydrophobic surface,which convents to superhydrophilic after oxygen annealing.First-principles calculations indicate that the adsorption energy of ZnO with water is about 0.2 eV at a distance of 2(A) when it is superhydrophilic,suggesting that lecithin can be absorbed on the hydrophilic surface stably at this distance and the bio-affinity can be enhanced under this condition.
基金This work is financially supported by the National Natural Science Foundation of China (No. 90101023) the National "973" Project of China (No. G20000683-1).
文摘A kind of novel broad-band superluminescent diodes (SLDs) using graded tensile-strained bulk InGaAs is developed. The graded tensile-strained bulk InGaAs is obtained by changing only group-Ⅲ trimethyl-gallium source flow during low-pressure metal organic vapor-phase epitaxy. At the injection current of 200 mA, the fabricated SLDs with such structure demonstrate full-width at half-maximum spectral width of 106 nm and the output light power of 13.6 mW, respectively.
基金This work was supported in part by the National Natural Science Foundation of China under Grant No. 60138010.
文摘Parallel optical coherence tomography is demonstrated using a 12-bit scientific-grade charge-coupled device array. A superluminescent diode in combination with a free-space Michelson interferometer was employed to achieve 10-μm axial resolution and 1.1-μm transverse resolution on a 902×575 /μm2 field of view. We imaged a test mirror and bovine retinal tissue using a four-step phase shift method.
文摘Laser drivers are an enabling factor to inertial confinement fusion, because laser diodes must be used instead of flash lamps. We discuss the limitations of laser diode arrays and show what steps the industry is taking. The pump power requirements of large-scale projects such as LIFE or Hi PER are within reach of semiconductor laser diode assemblies.Pulsed light output powers per laser bars have been around 300 W per bar, as in the Jenoptik 940 nm bars previously used for pumping the Yb:YAG slabs in the Di POLE project. By redesigning the semiconductor laser structures 500 W per bar is now commercially available for 808, 880 and 940 nm pump wavelengths. The construction of one inertial fusion power plant will require an amount of semiconductor laser chips in excess of the current annual production by two orders of magnitude. This adds to the engineering task of improving the device characteristics a challenge to production capacity.While the industry benefits from the recent boost in solid-state lighting that acts as a technology driver, cooperation between manufacturers will be imperative, and to this end we propose standardization efforts.
