Frequency stabilization at the sub-kilohertz level of an external cavity diode laser

Abstract

A simple external cavity diode laser (ECDL) in a Littrow configuration was established and actively frequency-stabilized by using a side-of-fringe stabilization technique. A wavelength tuning range of 60 nm for the spectral range between 1000 and 1060 nm was demonstrated by rotating the diffraction grating. A sub-kilohertz frequency stabilization of the ECDL was achieved. The linewidth of the laser was narrowed from 160 kHz to 400 Hz by laser frequency locking to a flank of a Fabry-Perot interferometer peak.

Advances in narrow linewidth diode lasers

“…In 2016, Shin et al [49] from the Australian National University proposed that Littrow-ECL consist of a gain chip with one-sided tilt output light and a blazed grating (1200 lines/mm) to achieve an output power of 300 mW at 600 mA, wide tuning in the range of 100 nm near the 1080 nm band, a Lorentz line width of 4.2 kHz at 22.5 ms, and an excellent wavelength stability (40 kHz for 11 h). In the same year, the side-of-fringe stabilization technology was adopted by Suleiman Demirel University in Turkey [50] to achieve active frequency stabilization of ECL. Its wavelength tuning range was 60 nm (1000-1060 nm), and its line width was narrowed from 160 KHz to 400 Hz.…”

Advances in narrow linewidth diode lasers

“…2016 年, 澳大利亚国立大学的 Shin 等 [49] 提出采用单边倾斜出光的增益芯片和闪耀光栅 (1200 线/mm) 构成 Littrow-ECL, 实现输出功率 300 mW@600 mA, 在 1080 nm 波段附近 100 nm 范围的宽调谐, 洛伦兹线宽 4.2 kHz@22.5 ms, 同时获 得优良的波长稳定性 (40 kHz@11 h). 同年, 土耳其苏莱曼 • 德米雷尔大学 [50] 采用一种 side-of-fringe 稳定技术, 实现了频率主动稳定 ECL, 其波长调谐范围为 60 nm (1000∼1060 nm), 线宽由 160 KHz 窄 化为 400 Hz. 随后, 苏莱曼 • 德米雷尔大学 [51] 又创新性地采用超低腔面反射率 (0.005%) 的增益芯片 结合双 Littrow 结构实现一种双纵模激射 ECL, 获得 120 nm (覆盖 1470∼1590 nm) 的波长调谐范围, 这种双波长光源适用于光传感、太赫兹波源、成像、双波长干涉仪、光开关、波分复用等应用领域.…”

Optical Bistability and Thermal Mode Hopping in External Cavity Feedback Semiconductor Lasers

“…The core of each scheme involves screening and locking the optical frequency in the external cavity, and then suppressing the edge mode noise to narrow the laser linewidth. In addition to the blazed grating, many excellent works have successively developed other devices to meet the requirements of the scheme, including Bragg volume grating [3][4][5], Fabry-Pérot etalon (FP) [6], fiber grating [7,8], planar lightwave circuit (PLC) [9][10][11], quantum dot lasers [12,13], etc. Many of them have been applied to engineering practices.…”