Compact wavelength-swept laser module with broadband spectrum range and high mode stability based on REC technique

We experimentally demonstrated a compact wavelength-swept laser module based on REC technology, featuring a wide spectral range and high mode stability. By employing reconstructed equivalent chirp (REC) technology, the fabrication of gratings was simplified, thereby reducing manufacturing costs. The cascaded <i>Y</i>-branch structure minimized structural complexity. The integration of an external SOA enhanced laser output power, and an isolator was inserted between the laser and SOA to maximize mode stability. At an SOA current of 250 mA, each laser channel provided a power amplification exceeding 25 mW. The proposed laser array exhibited a wavelength tunability exceeding 48 nm, with all channels achieving SMSRs greater than 40 dB. The wavelength scanning range of each channel was evaluated using a Fabry-Pérot (F-P) etalon with a free spectral range of 130 GHz, revealing scanning ranges exceeding 2 nm for all channels. This design offers a compact and high-performance solution for multi-parameter sensing applications.