1 W 1.06 µm DFB Laser with Record Efficiency

High-power and highly efficient sources of coherent light at 1.06 µm are essential for applications such as optical amplifiers, holography, frequency doubling, and material processing. To address these demands, we have developed a GaAs-based DFB laser featuring waveguide broadening (both horizontal and vertical), a low-loss structure, and an increased chip length of 4 mm, ensuring high power and efficiency. The laser chips were fabricated using our overgrowth-free process, allowing for improved scalability and reliability.

As a result, we have successfully developed an InGaAs quantum well-based 1.06 µm DFB laser, delivering up to 1 W of optical power with a power conversion efficiency (PCE) of 45% in continuous-wave (CW) mode. Based on our knowledge, these values represent world-record results for GaAs-based DFB lasers.

To ensure high beam quality, we have integrated an adiabatic spot size converter (SSC) with a 3 mm DFB section in a single chip, achieving a stable far-field divergence of 4×27 degrees FWHM. For 3 mm-long chips assembled in a standard 14-pin “butterfly” package, we achieved a fiber coupling efficiency of over 70% into single-mode fiber (SMF). Our well-controlled antireflection (AR) coating enabled a 40 nm detuning between the grating spectrum and the gain maximum, ensuring single-mode operation with a high side-mode suppression ratio (SMSR) exceeding 45 dB.

In addition to high power and efficiency, our developed laser design is also optimized for low phase noise operation. Using a self-heterodyning technique with an 8 km fiber delay line, we observed a full-width half-maximum (FWHM) spectral linewidth below 300 kHz across a wide range of operating conditions.
These lasers are ideal for high-power semiconductor applications that demand excellent emission characteristics, particularly in coherence-sensitive applications such as LiDAR systems and seed sources for optical amplifiers.

Our team is working on introduction this model into series.