High power DFB laser diodes

Abstract

We present a new design that reduces the far field angles and increases the threshold for catastrophic optical damage of distributed feedback lasers with lateral gratings. The layer structure consists of an asymmetric large optical cavity where the active region is located very close to the upper cladding layer. The position and large refractive index of the active region results in a mode profile that is suitable for good coupling to the lateral grating. A large mode diameter on the facets is achieved by tapering the ridge from its original width to sub-micron dimensions close to the facets. This taper pushes the optical mode down into the core of the large optical cavity, leading to an increase of the mode diameter. The concept is fully compatible with standard facet coating and passivation processes. We present 980 nm laser diodes based on this concept with 5.2° and 13° full-width half-maximum of the farfield and catastrophic optical damage thresholds of 1.6 W.

Two-dimensional pseudo-random optical phased array based on tandem optical injection locking of vertical cavity surface emitting lasers

“…This modest level of the required master laser diode optical power is mainly due to the very low injection locking light level that results from using the low cavity-Q VCSELs in the 2dimensional optical phased array. Both distributed Bragg reflector (DBR) and distributed feedback (DFB) laser diodes can readily provide >50 mW of single mode optical power [12]. Fig.…”