Crystalline garnet Bragg reflectors for high power, high temperature, and integrated applications fabricated by multi-beam pulsed laser deposition

Crystalline Bragg reflectors are of interest for high power, high temperature, and integrated applications. We demonstrate the automated growth of such structures by shuttered multi-beam pulsed laser deposition. Geometries include 145 layer stacks exhibiting >99.5% reflection and π phase-shifted designs. A crystalline grating strength-apodized sample was grown by mixing plumes to obtain layers with custom refractive indices. Peak reflection wavelength was tuneable with incident position, samples withstood temperatures of ∼750 °C, and film and substrate have been shown to withstand incident pulsed laser fluences of up to ∼33 J cm⁻².