# Thermo-Tuning Fourier Transform Spectrometer Based on SU-8 Waveguide

## TL;DR

This paper presents a compact, low-power on-chip Fourier transform spectrometer using SU-8 waveguide technology for efficient spectral analysis.

## Contribution

A novel thermo-tuned SU-8 waveguide-based FTS with a small footprint and low power consumption is developed and characterized.

## Key findings

- The FTS device has a footprint of 2 × 12 mm² and consumes a maximum of 2.2 W.
- It achieves a spectral resolution of less than 20 nm and a bandwidth of approximately 100 nm.
- The device successfully retrieves light source spectra using a Fourier transform algorithm.

## Abstract

On-chip Fourier transform spectrometer (FTS) is a promising technology due to the compact size, low cost, and relatively high throughput. In this work, we design, fabricate, and characterize a Mach-Zehnder interferometer (MZI) FTS based on SU-8 polymer waveguide. The optical path length difference of MZI is tuned by a heater with a maximum power consumption of 2.2 W. The interference signal is analyzed by Fourier transform algorithm, to retrieve the spectrum of light source. The footprint of the fabricated FTS device is only 2 × 12 mm2, with the spectral bandwidth of ~100 nm and resolution <20 nm.