Highly compact, low RIN, all-in-one 14-pin butterfly laser driver module compatible with switching power sources

We present a highly compact, low relative intensity noise (RIN) all-in-one continuous-wave (CW) laser driver module designed for standard 14-pin butterfly-package laser diodes. The proposed driver delivers up to 500 mA of low-noise output current and provides closed-loop temperature control of the internal thermoelectric cooler (TEC) using a conventional switched TEC driver. In compact laser systems, low-RIN driver implementations typically require extensive passive filtering and large board area to mitigate noise originating from switching power supplies and TEC drivers, which complicates system integration. In contrast, the proposed design achieves effective suppression of noise contributions from DC–DC power conversion and TEC switching stages within a footprint of only 20 × 20 mm2. The performance of the driver is experimentally evaluated using two representative 1550 nm butterfly-package laser sources: a distributed-feedback (DFB) laser and an external-cavity laser (ECL). Light–current–voltage (LIV) characteristics and relative intensity noise are measured over operating temperatures of 10 °C, 25 °C, and 40 °C. Experimental results demonstrate system-level RIN below −125 dBc/Hz at maximum operating currents of 400 mA for the DFB laser and 100 mA for the ECL, while maintaining stable optical output and temperature control. These results demonstrate the suitability of the proposed driver for compact, low-noise photonic applications requiring compatibility with switching-based power architectures and wide temperature operation.