With the objective of enabling wide tuning characteristics of a semiconductor light source for CO ₂ gas sensing, we demonstrate a 2.0- $\mu \text{m}$ wavelength superstructure grating (SSG-) DBR laser for the first time. SSGs for the 2.0- $\mu \text{m}$ wavelength with seven reflection peak characteristics were designed and introduced to a DBR laser with strained InGaAs multi-quantum-wells (MQWs). The wavelength shift for a single reflection peak due to the carrier-plasma effect was as high as 11 nm, which is sufficient for quasi-continuous tuning characteristics of the SSG-DBR laser. We also found that all seven SSG modes could be individually oscillated by controlling the front and rear SSG-DBR currents. Our evaluation of the lasing characteristics for 40 consecutive channels with 100-GHz spacing show that the lasing wavelength was accurately tuned from 1990.7 nm for the first channel to 2043.4 nm for the 40th channel by using the seven SSG modes. These results demonstrate that the fabricated 2.0- $\mu \text{m}$ wavelength SSG-DBR laser successfully attained a quasi-continuous wavelength tuning of over 50 nm.

中文翻译：

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2.0-μm 波长超结构光栅 (SSG-) 分布式布拉格反射激光器，调谐范围超过 50 nm

为了实现用于 CO ₂气体传感的半导体光源的宽调谐特性 ，我们展示了一个 2.0- $\mu \text{m}$ 波长超结构光栅（SSG-）DBR激光器首次出现。2.0-的SSG $\mu \text{m}$ 设计了具有七个反射峰特性的波长，并将其引入具有应变 InGaAs 多量子阱 (MQW) 的 DBR 激光器。由于载流子等离子体效应，单个反射峰的波长偏移高达 11 nm，这足以满足 SSG-DBR 激光器的准连续调谐特性。我们还发现所有七种 SSG 模式都可以通过控制前后 SSG-DBR 电流来单独振荡。我们对间隔为 100 GHz 的 40 个连续通道的激光特性的评估表明，通过使用七种 SSG 模式，可以将激光波长从第一个通道的 1990.7 nm 精确调谐到第 40 个通道的 2043.4 nm。这些结果表明制造的 2.0- $\mu \text{m}$ 波长 SSG-DBR 激光器成功实现了超过 50 nm 的准连续波长调谐。