760nm vertical-cavity surface-emitting laser for oxygen sensing

Vertical cavity surface-emitting lasers (VCSELs) have a wide range of applications in optical communications, optical displays, gas sensing, and lidar due to their advantageous properties, including low power consumption, compact size, superior beam quality, and high reliability1. Among them, the wavelength bands at 761 nm and 763 nm are of particular significance for applications in metallurgical processes, real-time hypoxemia monitoring, and pharmaceutical and food safety. The operational principle of these systems is predicated on tunable diode laser absorption Spectroscopy (TDLAS) technology. This technology employs the narrow linewidth and wavelength-shifting properties of tunable diode lasers at varying injection currents to scan specific gas absorption lines. To date, the above approach has been shown to offer significant advantages, including excellent selectivity, sensitivity, rapid response, online measurement capability, and strong resilience to background spectral interference. The present study proposes the development of a VCSEL with stable single-mode output, achieved through a combination of an oxidized confinement structure and a surface grating structure. The device displays an activation voltage of 1.5 V and a threshold current of 0.4 mA. Operating at 2 mA and 2.3 V, the VCSEL achieves an output power of 1.2 mW. Furthermore, The VCSEL under scrutiny in this study boasts a center wavelength of 763 nm, and a side mode suppression ratio (SMSR) of approximately 43 dB. In conclusion, the VCSEL that has been manufactured exhibits both exceptional beam quality and favorable electrical characteristics. These findings indicate a significant potential for the VCSEL to be utilized in applications that focus on oxygen sensing.