NATRON µcleave process
Conventional diode laser facet preparation requires a semiconductor wafer to first be notched to introduce a crystal defect on the epi-side and then an acoustic wave propagates the defect to yield near atomically flat facets. In the case of high Al-fraction AlGaAs laser materials the surface chemistry of these newly exposed ternary and quaternary facet components changes rapidly in air; this change strongly limits both the lifetime and the peak optical power that can be obtained by these lasers. Whilst Helia has long been involved in processes that partially restore the facet chemistry to the bulk properties by means of pre coating multi-gas etches and novel passivation materials, these do not offer the same characteristics as had no chemical change occurred at all as afforded by in-vacuu cleaving.
Helia Photonics, in conjunction with SUPA (Scottish Universities Physics Alliance), are in the advanced stages of building a novel apparatus that allows the cleaving and in-situe coating of hundreds of laser bars without exposure to air. Part of this development includes design and fabrication of some of the world’s smallest micro-magnetrons.
Process viability date is due November 2016