Magneto-optical spectroscopy based on pump-probe strobe light

TL;DR

This paper introduces a novel pump-probe strobe light spectroscopy technique for sensitive, high-resolution detection of magneto-optical dynamics in hybrid magnonic systems, capable of operating at gigahertz frequencies.

Contribution

It presents a new pump-probe scheme combining microwave and optical pulses with variable widths for enhanced magneto-optical sensitivity and coherence in magnetization dynamics detection.

Findings

Effective detection of magnetization dynamics in Y3Fe5O12 films.

Maintains high sensitivity at short pulse durations (1.5 ns microwave, 80 ps optical).

Operates reliably at a 7 MHz clock rate, covering gigahertz frequency range.

Abstract

We demonstrate a pump-probe strobe light spectroscopy for sensitive detection of magneto-optical dynamics in the context of hybrid magnonics. The technique uses a combinatorial microwave-optical pump-probe scheme, leveraging both the high-energy resolution of microwaves and the high-efficiency detection using optical photons. In contrast to conventional stroboscopy using a continuous-wave light, we apply microwave and optical pulses with varying pulse widths, and demonstrate magnetooptical detection of magnetization dynamics in Y3Fe5O12 films. The detected magneto-optical signals strongly depend on the characteristics of both the microwave and the optical pulses as well as their relative time delays. We show that good magneto-optical sensitivity and coherent stroboscopic character are maintained even at a microwave pump pulse of 1.5 ns and an optical probe pulse of 80 ps, under a 7 megahertz clock rate, corresponding to a pump-probe footprint of ~1% in one detection cycle. Our results show that time-dependent strobe light measurement of magnetization dynamics can be achieved in the gigahertz frequency range under a pump-probe detection scheme.