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

Area of Science:

• Photonics and Laser Technology
• Optical Engineering
• Materials Science for Photonics

Background:

• Wavelength-swept lasers are crucial for applications like optical coherence tomography and spectroscopy.
• Existing laser designs often face challenges with complexity, cost, and stability.
• There is a need for compact, high-performance laser modules with wide tuning ranges.

Purpose of the Study:

• To demonstrate a compact wavelength-swept laser module utilizing reconstructed equivalent chirp (REC) technology.
• To achieve a wide spectral range and high mode stability in the laser module.
• To reduce manufacturing costs through simplified grating fabrication.

Main Methods:

• Employed reconstructed equivalent chirp (REC) technology for simplified grating fabrication.
• Utilized a cascaded Y-branch structure to minimize complexity.
• Integrated an external semiconductor optical amplifier (SOA) for enhanced output power.
• Incorporated an isolator to maximize mode stability.

Main Results:

• Achieved a wavelength tunability exceeding 48 nm across all laser channels.
• Obtained side-mode suppression ratios (SMSRs) greater than 40 dB for all channels.
• Demonstrated power amplification exceeding 25 mW per channel at an SOA current of 250 mA.
• Measured wavelength scanning ranges exceeding 2 nm for each channel using a Fabry-Pérot etalon.

Conclusions:

• The developed laser module is compact and offers high performance.
• REC technology simplifies fabrication and reduces costs.
• The laser is suitable for multi-parameter sensing applications requiring wide spectral range and stability.