纯增益耦合机制在InP基DFB半导体激光器中的实现

DFB semiconductor laser is the basic elemental component in optical communication systems, and has a great market in national key application direction such as "broadband China", "big data" , "cloud computing" and so on. Right now DFB lasers in the market are all based on index coupled structure, half of the light energy is wasted because of both facet lasing. Meanwhile, these laser chips rely on complex and expensive processing technology such as electron beam lithography and second epitaxial, which tend to reduce the yield of final products and raise the cost. In this program, we propose the realization on purely gain coupled mechanism in InP based DFB semiconductor lasers. The introduction of periodic anode will bring gain coupled iΔκ type DFB effect to generate single longitude mode, avoiding the mode hopping effect caused by index coupling. Two sets of anodes are designed, so as to bring larger tuning range by switching the current injenction as well as swtiching the wavelength. The component doesn't need complex gratings in the chip, and immune to facet phase effects，which means high reflection coating and antireflection coating can be applied to make single facet lasing, increasing power and reducing wasted laser to improve efficiency. No second epitaxy is needed. Our structure has a large processing tolerance, low cost, and can be commercialized conveniently. The final goal of the program is to acquire the physical model and the principles of carriers drifting, and make single DFB lasers with main parameters exceed the existing commercialized products as: power ≥20mW, efficiency≥5~6%, tunning range ≥4nm (international level ~3nm), other parameters reach the same level as commercial products as: linewidth ≤10MHz, SMSR＞30dB, and center wavelength is between 1550±20nm.

本项目针对国家在宽带中国、大数据、云计算等重大应用方向的光通信基础元器件：DFB半导体激光器，提出了“纯增益耦合机制在InP基DFB半导体激光器中的实现”：利用周期性金属电极形成高阶iΔκ型DFB机制，排除折射率耦合带来的跳模问题；通过两套不同周期的电极注入，实现波长可切换，扩大调谐范围；器件不需制备微纳尺度复杂光栅，不受解理端面相位影响；可AR/HR镀膜增加功率和效率；无需二次外延技术。项目拟获得高阶iΔκ型DFB的物理模型、载流子扩散机制，并在实验上获得DFB激光器件初样，实现功率、效率和调谐范围指标高于现有商用产品指标：功率≥20mW，效率≥5~6%，波长可调谐范围≥4nm(国际水平~3nm)，其他指标达到商用产品指标：线宽≤10MHz，SMSR＞30dB，波长位于1550±20nm之间。

DFB激光器广泛应用于光通信、智能感知激光雷达和原子泵浦（量子精密测量）领域中。本项目主要研究了高阶iΔκ型DFB芯片。在本项目资助下，获得780nm、905nm和1550nm三个波段的iΔκ型DFB芯片初样，关键性能指标如下：①780nm波段功率≥140mW，效率11.3%，调谐范围≥17.5nm（远高于国际水平~3nm），高于市场上成熟的商用DFB激光参数， SMSR≥36.11dB，线宽≤6.05MHz。②905nm波段未镀膜功率＞100 mW/facet左右，效率>19%，SMSR＞41dB，单管调谐范围＞19 nm，4信道列阵的调谐范围可达48 nm，线宽0.85GHz。③1550nm波段功率≥400mW，调谐范围＞6nm，SMSR＞55dB，线宽≤18MHz。上述芯片的研发可以推动光通信领域、激光雷达领域和量子陀螺仪导航等原子泵浦领域的关键核心光源国产化。