# Enhanced Sensitivity of Sub-THz Thermomechanical Bolometers Exploiting Vibrational Nonlinearity

## TL;DR

This paper introduces a new method to improve the sensitivity of sub-THz detectors using interference and nonlinearity, avoiding the need for high Q-factors.

## Contribution

The novel approach uses engineered response curves to reduce noise equivalent power without increasing Q-factors.

## Key findings

- Signal transduction along engineered response curves reduces NEP in sub-THz detectors.
- A NEP of ∼30pW/Hz is achieved with optimized absorbing layers in electrical read-out detectors.

## Abstract

A common approach to detecting weak signals or minute
quantities
involves leveraging the localized spectral features of resonant modes,
whose sharper lines (i.e., high Q-factors) enhance transduction sensitivity.
However, maximizing the Q-factor often introduces technical challenges
in fabrication and design. In this work, we propose an alternative
strategy to achieve sharper spectral features by using interference
and nonlinearity, all while maintaining a constant dissipation rate.
Using far-infrared thermomechanical detectors as a test case, we demonstrate
that signal transduction along an engineered response curve slope
effectively reduces the detector’s noise equivalent power (NEP),
achieving
∼30pW/Hz
NEP for electrical read-out, sub-THz detectors
with an optimized absorbing layer.