Feng Tao, Hosoda Takashi, Shterengas Leon, Kipshidze Gela, Stein Aaron, Lu Ming, Belenky Gregory
Appl Opt. 2017 Nov 1;56(31):H74-H80. doi: 10.1364/AO.56.000H74.
The laterally coupled distributed feedback (LC-DFB) GaSb-based type-I quantum well cascade diode lasers using the second- and the sixth-order gratings to stabilize the output spectrum near 3.22 μm were designed and fabricated. The laser heterostructure contained three cascades. The devices were manufactured using a single dry etching step defining the ∼5-μm-wide ridge with ∼5-μm-wide gratings sections adjacent to the ridge sides. The grating coupling coefficients were estimated to be about 1 cm. The stability of the single-frequency operation was ensured by alignment of the DFB mode to the relatively wide gain peak. The 2-mm-long second-order LC-DFB lasers generated above 10 mW of continuous-wave (CW) output power at 20°C in epi-side-up configuration and demonstrated power conversion efficiency above 2%. The sixth-order LC-DFB lasers showed lower efficiency but still generated several milliwatts of CW output power. The devices demonstrated a CW current tuning range of about 3.5 nm at the temperature of 20°C.
设计并制造了基于锑化镓（GaSb）的横向耦合分布反馈（LC-DFB）I型量子阱级联二极管激光器，该激光器使用二阶和六阶光栅来稳定3.22μm附近的输出光谱。激光异质结构包含三个级联。这些器件通过单个干法蚀刻步骤制造，该步骤定义了约5μm宽的脊以及与脊侧相邻的约5μm宽的光栅部分。光栅耦合系数估计约为1cm。通过将DFB模式对准相对较宽的增益峰值，确保了单频操作的稳定性。在20°C下，采用外延面朝上配置的2mm长二阶LC-DFB激光器产生了超过10mW的连续波（CW）输出功率，并且功率转换效率超过2%。六阶LC-DFB激光器效率较低，但仍产生了几毫瓦的CW输出功率。在20°C的温度下，这些器件展示了约3.5nm的CW电流调谐范围。
