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Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Long-external-cavity distributed Bragg reflector laser with subkilohertz intrinsic linewidth
Qian Lin1, Mackenzie A Van Camp, Hao Zhang
1Department of Physics, MIT-Harvard Center for Ultracold Atoms and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Optics Letters
|June 5, 2012
Summary
A new 780 nm distributed Bragg reflector laser uses a 3.6 m optical fiber external cavity to achieve a 300 Hz intrinsic linewidth. This compact laser system offers narrow linewidth and low high-frequency noise for advanced applications.
Area of Science:
- Atomic, Molecular, and Optical Physics
- Laser Physics and Photonics
Background:
- Achieving narrow intrinsic linewidths is crucial for high-precision optical measurements and advanced communication systems.
- Distributed Bragg reflector (DBR) lasers offer a compact platform, but often suffer from higher frequency noise.
Purpose of the Study:
- To develop a simple, compact, and robust 780 nm DBR laser with subkilohertz intrinsic linewidth.
- To investigate methods for significantly reducing laser frequency noise.
Main Methods:
- Implementation of a 3.6 m optical fiber external cavity to reduce laser frequency noise.
- Characterization of the frequency noise spectral density and intrinsic Lorentzian linewidth.
- Analysis of the impact of feedback power and current variations on linewidth.
Main Results:
- The external cavity reduced frequency noise spectral density by over 33 dB at frequencies above 100 kHz.
- An intrinsic Lorentzian linewidth of 300 Hz was achieved.
- Low-frequency noise can be further suppressed via stabilization to an external reference cavity.
Conclusions:
- The developed 780 nm DBR laser provides a tunable, narrow linewidth, and low high-frequency noise source.
- The system is well-suited for applications like coherent optical communication, optical clocks, and cavity quantum electrodynamics (QED) experiments.
