Open AccessFrequency locking of semiconductor lasers to RF oscillators using hybrid-integrated opto-electronic oscillators with dispersive delay lines
Author(s) -
Zhe Xuan,
Lixiong Du,
Firooz Aflatouni
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.010729
Subject(s) - laser , optics , optoelectronics , semiconductor laser theory , photonics , materials science , photonic integrated circuit , radio frequency , physics , telecommunications , computer science
Direct frequency locking of lasers to RF oscillators has many applications such as high resolution optical frequency synthesis, coherent optical communication, spectroscopy, sensing, and imaging. Here we present a hybrid-integrated opto-electronic loop that directly frequency locks a semiconductor laser to an RF synthesized source using an opto-electronic oscillator with a dispersive optical delay line. Cascaded ring filters, operating near the resonance frequency, provide an enhanced chromatic dispersion with a compact footprint. The electronic chip is integrated in the GlobalFoundries 180 nm CMOS SOI technology and the photonic chip is integrated in the IME 180 nm SOI technology. A tracking range of 0.5 GHz is achieved while consuming 33 mW power. The proposed scheme is used to frequency lock a commercially available DFB laser, reducing the laser frequency fluctuations by an order of magnitude compared to the free-running case.