One-dimensional optomagnonic microcavities for selective excitation of perpendicular standing spin waves

TL;DR

This paper introduces a method to selectively excite perpendicular standing spin waves in an optomagnonic microcavity using ultrashort laser pulses, enabling precise control for quantum technology applications.

Contribution

It demonstrates a novel optical technique for selective excitation of PSSWs in a microcavity, enhancing control over spin wave modes for quantum applications.

Findings

Efficient excitation of specific PSSW modes achieved

Optical cavity modes enable spatially non-uniform power distribution

Selective excitation depends on matching wavevectors

Abstract

Here we propose a method of the excitation of perpendicular standing spin waves (PSSWs) of different orders in an optomagnonic microcavity by ultrashort laser pulses. The microcavity is formed by a magnetic dielectric film surrounded by dielectric non-magnetic Bragg mirrors. Optical cavity modes in the magnetic layer provide concentration and strongly non-uniform distribution of the optical power over the layer thickness and therefore induce the effective field of the inverse Faraday effect also spatially non-uniform. It results in excitation of PSSWs. PSSWs whose wavevector is closest to the wavevector characterizing distribution of the inverse Faraday effect field are excited most efficiently. Consequently, a key advantage of this approach is a selectivity of the PSSW excitation which allows to launch PSSWs of required orders only. All-optical operation of the optomagnonic cavities opens new possibilities for their applications for quantum technologies.