Low vibration high numerical aperture automated variable temperature Raman microscope

TL;DR

This paper introduces a novel low-vibration, high-NA automated variable temperature Raman microscope with enhanced stability and efficiency, enabling detailed studies of challenging samples like Bi2Se3 and V2O3 across phase transitions.

Contribution

It presents a new design of a closed-cycle Raman microscope with full polarization rotation, improving measurement stability and sensitivity for low-signal, thermally sensitive samples.

Findings

Achieved high temperature resolution in challenging samples

Demonstrated stability and efficiency improvements over previous designs

Enabled detailed phase transition studies in low-conductivity materials

Abstract

Raman micro-spectroscopy is well suited for studying a variety of properties and has been applied to wide- ranging areas. Combined with tuneable temperature, Raman spectra can offer even more insights into the properties of materials. However, previous designs of variable temperature Raman microscopes have made it extremely challenging to measure samples with low signal levels due to thermal and positional instability as well as low collection efficiencies. Thus, contemporary Raman microscope has found limited applicability to probing the subtle physics involved in phase transitions and hysteresis. This paper describes a new design of a closed-cycle, Raman microscope with full polarization rotation. High collection efficiency, thermal and mechanical stability are ensured by both deliberate optical, cryogenic, and mechanical design. Measurements on two samples, Bi2Se3 and V2O3, which are known as challenging due to low thermal conductivities, low signal levels and/or hysteretic effects, are measured with previously undemonstrated temperature resolution.