title: Low loss depressed cladding waveguide inscribed in YAG:Nd single crystal by femtosecond laser pulses.
abstract: A depressed cladding waveguide with record low loss of 0.12 dB/cm is inscribed in YAG:Nd(0.3at.%) crystal by femtosecond laser pulses with an elliptical beam waist. The waveguide is formed by a set of parallel tracks which constitute the depressed cladding. It is a key element for compact and efficient CW waveguide laser operating at 1064 nm and pumped by a multimode laser diode. Special attention is paid to mechanical stress resulting from the inscription process. Numerical calculation of mode distribution and propagation loss with the elasto-optical effect taken into account leads to the conclusion that the depressed cladding is a dominating factor in waveguide mode formation, while the mechanical stress only slightly distorts waveguide modes.
authors.affiliation: Photonics Research Group, Aston University, Birmingham B4 7ET, UK. a.okhrimchuk@aston.ac.uk
authors.forename: Andrey
authors.initials: A
authors.lastname: Okhrimchuk
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mezentsev
authors.forename: Alexander
authors.initials: A
authors.lastname: Shestakov
authors.forename: Ian
authors.initials: I
authors.lastname: Bennion