Understanding Pound-Drever-Hall locking using voltage controlled radio-frequency oscillators: An undergraduate experiment

TL;DR

This paper presents an undergraduate experiment demonstrating Pound-Drever-Hall frequency stabilization of an 800 MHz oscillator using radio-frequency electronics, enabling hands-on learning of feedback control and material properties.

Contribution

It introduces a cost-effective, safe, and accessible radio-frequency experiment to teach frequency stabilization and thermal expansion measurement techniques.

Findings

Successful stabilization of oscillator frequency to cavity resonance.

Students can measure thermal expansion coefficients of different materials.

The experiment enhances understanding of feedback control and RF electronics.

Abstract

We have developed a senior undergraduate experiment that illustrates frequency stabilization techniques using radio-frequency electronics. The primary objective is to frequency stabilize a voltage controlled oscillator to a cavity resonance at 800 MHz using the Pound-Drever-Hall method. This technique is commonly applied to stabilize lasers at optical frequencies. By using only radio-frequency equipment it is possible to systematically study aspects of the technique more thoroughly, inexpensively, and free from eye hazards. Students also learn about modular radio-frequency electronics and basic feedback control loops. By varying the temperature of the resonator, students can determine the thermal expansion coefficients of copper, aluminum, and super invar.