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Updated: Jun 11, 2026
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Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Summary
Two physically separated laser diode arrays were successfully injection-locked to a single master laser, demonstrating high mutual coherence (0.96 ± 0.06) and minimal spatial phase variation for coherent beam combination.
Area of Science:
- Optics and Photonics
- Laser Physics
Background:
- Injection-locking is a technique to synchronize laser outputs.
- Coherent combination of multiple laser sources can increase output power and improve beam quality.
Purpose of the Study:
- To investigate the coherence properties of simultaneously injection-locked laser diode arrays.
- To determine the feasibility of coherent combination for these systems.
Main Methods:
- Simultaneous injection-locking of two physically separated laser diode arrays to a common master laser.
- Measurement of the modulus of the mutual coherence function.
- Analysis of the spatial phase difference between the output beams.
Main Results:
- A high modulus of mutual coherence (0.96 ± 0.06) was achieved, close to the theoretical maximum of 1.
- Spatial phase variation between the beams was less than 0.05 waves (λ/20), excluding a linear tilt.
- A linear phase difference growth was observed due to beam tilt.
Conclusions:
- Simultaneous injection-locking can yield highly coherent laser diode array outputs.
- The demonstrated coherence is sufficient for coherent beam combination applications.
- Requirements for successful coherent combination are discussed based on experimental findings.
