Long-lifetime 632.8 nm DBR laser diode solution for HeNe replacement

Helium-neon (He-Ne) lasers are one of the most widely used gas lasers worldwide. The red He-Ne laser, operating at wavelength of 632.8 nm, is used in a broad range of applications, including spectroscopy, microscopy, interferometry, and metrology, to name a few. Its desirable characteristics include a stable output wavelength and power, high monochromaticity, and coherence and temporal stability over distances and time. Despite being relatively compact for a gas laser, He-Ne lasers typically have cavity lengths from 15 cm up to 1 m, depending on the required output power. Furthermore, they require high-voltage power supplies and have low electrical-to-optical efficiency. These constraints limit their practicality and have driven the development of alternative laser sources with smaller footprints and lower operating voltages. In this paper, we present performance and reliability results of 632.8 nm distributed Bragg reflector (DBR) laser diode specifically designed to replace conventional He-Ne lasers. These laser diodes operate in a single spatial mode and at a single optical frequency. The emission wavelength is precisely defined by on-chip DBR gratings and finetuned by operating temperature and current, enabling a compact and robust alternative to traditional He-Ne systems. Stable operation is demonstrated at 10 mW output power with minimal performance degradation. The devices exhibit a narrow linewidth of less than 10 MHz across its operating conditions. For effortless replacement of He-Ne lasers, form-factor from 14-pin butterfly package with driver electronics up to OEM module can be accommodated.