Denuwan Vithanage

Phd Candidate

Denuwan Vithanage

Phd Candidate

Projects

Spring 2021 – Worked on optimizing and stabilizing a Littrow-configuration Extended-Cavity Diode Laser (ECDL) initially designed by a peer, for use in high-resolution molecular spectroscopy.

  • Resolved optical and mechanical alignment issues to achieve stable beam collimation.
  • Implemented thermal control using multi-stage thermoelectric cooling (TEC) and optimized PID feedback.
  • Reduced frequency drift through active etalon temperature stabilization and vibration isolation.
  • Integrated data acquisition via LabVIEW and GPIB communication for automated spectral monitoring.
  • Applied the stabilized system to record Li₂ molecular transition spectra with improved frequency stability (<150 MHz drift over 1.5 hours).

This project enhanced the precision of laser-based molecular collision experiments and contributed to long-term stability improvements in the lab’s spectroscopy systems.

Design and Construction of an Extended-Cavity Diode Laser (ECDL)
Miami University — BEC Laboratory

  • Designed and built a Littrow-configuration ECDL for high-resolution spectroscopy of rubidium atoms.
  • Aligned collimation optics, diffraction grating, and feedback cavity to achieve single-mode operation.
  • Characterized wavelength tunability and integrated the system with a saturated absorption spectroscopy (SAS) setup for frequency locking.

Implementation of a Magneto-Optical Trap (MOT) for ⁸⁷Rb
Miami University — Bose-Einstein Condensate (BEC) Apparatus

  • Constructed and aligned six-beam MOT optics using diode laser systems, quarter-wave plates, and beam splitters.
  • Calibrated anti-Helmholtz coils and optimized laser detuning and magnetic field gradients for atom trapping.
  • Characterized trap loading efficiency through fluorescence imaging and beam diagnostics.
Completed Optical System
Completed MOT

Design and Assembly of Magnetic-Coil Transfer System
Miami University — Bose-Einstein Condensate (BEC) Apparatus

  • Designed and fabricated a magnetic-coil transfer system enabling transport of ultracold atoms from the MOT chamber 2 to the science cell.
Magnetic Coil Transfer System