Development of ultrahigh performance semiconductor lasers for photonic information infrastructure

1.吸收栅型增益耦合分布反馈激光器的研制我们研制了基于吸收栅型结构的1.55 nm波段GC分布反馈激光器。有源层为压缩应变InGaAsP多量子阱，吸收光栅层为InGaAs。该器件在室温下连续工作，阈值电流为20-30 mA，实现了高产额单模激光输出，边模抑制为40-55dB，且不需要在端面涂覆减反射膜。2.外反射抗扰性的特性研究了上述激光器的抗外反射特性。波长微调我们提出了波分复用光通信系统中的波长微调的新概念，并对其实现进行了研究。首先，利用光致折射率ch…进行波长修剪在硫化物玻璃中尝试了更多的角度，并开发了一种新的结构，其中硫化物与DFB激光有源层一起加载。在He-Ne激光照射下，在1.55微米处实现了0.14 nm波长的调谐。其次，尝试了基于光吸收诱导量子阱无序的波长调谐，并利用YAG激光实现了0.36 nm的调谐。4.首次采用四步金属有机气相外延(MOVPE)方法制备了GC-DFB激光三极管。5.模拟调制失真的分析与测量用一种新的数值方法分析了吸收栅型GC DFB激光器中的模拟调制失真。结果发现，由于有源层中的增益压缩被光栅中的吸收压缩所抵消，二次谐波失真被减小。6.具有量子线有源区的GC DFB激光器的研制首次利用V型槽衬底上的MOVPE生长，成功地制作了具有InGaAs应变量子线有源区的GC DFB激光器。较少

1.Development of absorptive-grating gain-coupled (GC) distributed-feedback (DFB) lasersWe fabricated and developed 1.55mum wavelength band GC DFB lasers based on absorptive grating structure. A compressively strained InGaAsP multiple quantum well was used as an active layr, and InGaAs was used as the absorptive grating layr. The device operated at room temperature in CW with threshold current of 20-30mA.We achieved high-yield single-mode lasing with 40-55dB side mode suppression without applying antireflection coating on the facets.2.Characterization of external reflection immunityExternal reflection immunity of the above lasers was characterized. Their critical feedback level was found to be improved with increasing gain coupling coefficient.3.Wavelength trimmingWe proposed "wavelength trimming", a new concept toward wavelength division multiplexed optical communication systems, and investigated its realization. First, the wavelength trimming utilizing Photoinduced refractive index ch … More ange in chalcogenide glasses was tried, and developed a new structure where the chalcogenide was loaded alongside the DFB laser active layr. By irradiating He-Ne laser beam, we demonstrated 0.14nm wavelength trimming at 1.55mum. Next, the wavelength trimming based on photo-absorption-induced disordering of quantum wells was tried, and 0.36nm trimming was accomplished by YAG laser irradiation.4.Fabrication of GC DFB laser triodeGC DFB laser triodes have successfully been fabricated for the first time by four step metal organic vapor phase epitaxy (MOVPE). Changes of absorption coefficient in the absorptive grating and of the coupling coefficients by applying voltage to the third terminal have experimentally been demonstrated.5.Analysis and measurement of analog modulation distortionWe analyzed analog modulation distortion in GC DFB lasers of absorptive grating type by a newly-developed numerical method. As a result, the second harmonic distortion was found to be reduced due to cancellation of gain compression in the active layr by absorption compression in the grating. A preliminary experiment was conducted to confirm the above theoretical prediction.6.Fabrication of a GC DFB laser with quantum wire active regionBy making use of MOVPE growth on V-grooved substrates, a GC DFB laser with InGaAs strained quantum wire active region has successfully been fabricated for the first time. Less