Engineering of Form Factor in Rotationally Symmetric Photonic Cavities for Faster Axion Searches

TL;DR

This paper presents a method to engineer the form factor in rotationally symmetric photonic cavities using higher-order modes, enabling faster axion searches across larger mass ranges by increasing scan speed.

Contribution

It introduces a novel approach to enhance the form factor in photonic cavities through higher-order modes, extending axion detection capabilities beyond current limits.

Findings

Higher-order modes produce larger form factors.

Scan speed increases proportionally to the square of the form factor and quality factor.

Method enables probing larger axion mass ranges.

Abstract

Form factor can be engineered in photonic cavities such that it dramatically increases the scan speed of axion haloscope detectors. Using higher-order modes of a photonic cavity, we can probe axions at larger mass ranges beyond the reach of current detectors that rely on conventional copper cavities. The main idea is to produce a higher-order mode with longitudinal field distribution that has relatively high amplitude away from both the cavity axis and the cavity walls such that it results in a relatively large form factor and maintains a high-quality factor. The detector scan speed significantly increases as it is proportional to the square of the form factor multiplied by the quality factor.