Diode laser frequency locking to atomic transition from metastable level

• Grant number: 25/22836-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2026
• End date: December 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Raul Celistrino Teixeira
• Grantee: Antonio Zanetti Aguiar
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

This undergraduate research project aims to frequency-lock a single-mode diode laser using a strontium gas excited to different metastable energy levels using a see-through cathode lamp as a frequency reference. The diode laser to be locked is applied in a cold atoms experiment to depopulate the metastable 5s5p 3P2 atomic level, which is populated during the optical cooling process. The cathode lamp produces a sample of atoms in the metastable 5s5p 3P2 level, which will be interrogated by a laser beam whose frequency we want to stabilize; The lamp's see-through geometry allows the laser beam to pass through the sample of excited atoms. In this project, the student will implement a frequency lock-in system based on a saturated absorption signal from the 5s5p 3P2 - 5s5d 3D2 atomic transition. The student will be responsible for implementing the entire optical scheme for obtaining the saturated absorption signal with the cathode lamp, optimizing this signal, and implementing the stabilization using a commercial electronic circuit.