High Peak Power Laser Diodes for Eye Safe LIDAR with Integrated Wavelength Locking Element

We report on the development of high peak-power broad-area laser diodes emitting in the 1.5 pm wavelength band for eye-safe LIDAR applications. The laser contain a monolithically integrated surface grating section for wavelength stabilization. The performance merits of the wavelength stabilized laser is benchmark against traditional Fabry-Pérot diodes fabricated within the same processing batch and having identical quantum-well design. The study demonstrates the efficacy of the surface-grating applied to broad-area lasers and the benefits rendered possible for decreasing the spectral linewidth and reducing the temperature drift of the wavelength. This type of high-power light source can improve the signal-to-noise ratio of eye-safe time-of-flight LIDARs in bright illumination conditions by making possible the use of narrow band-pass filters for reducing the ambient sunlight. Moreover, the same advantage to reject ambient signal is expected in other applications such as gated imaging [1], or when using a pulsed laser as the illuminator in high speed imaging applications. In addition, the variation in the emission wavelengths from wafer-to-wafer and from chip-to-chip is reduced compared to non-stabilized lasers.