Linewidth Characterization of Integrable Slotted Single-Mode Lasers

Abstract

A single-mode laser platform has been developed with a simple and high-yield fabrication based on etched slots. We present linewidth measurements on such lasers, which are fabricated without any regrowth steps. The group of slots placed on one side of laser cavity provides sufficient reflectivity for lasing, which allows the laser to be integrated with other devices such as semiconductor optical amplifiers and modulators. The laser with an effective cavity length of 450 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> m exhibits a threshold current of 31 mA and a side-mode suppression ratio of 48 dB. The laser shows a minimum Lorentzian linewidth of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 720$ </tex-math></inline-formula> kHz at room temperature. The linewidth remains <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 1$ </tex-math></inline-formula> MHz within the temperature range of 10 °C–60 °C.