High-power, single-frequency, narrow-linewidth lasers emitting at tailored wavelength are desired for many applications, especially for precision spectroscopy. By way of a free-space resonator, optically pumped semiconductor lasers (OPSLs), a.k.a. vertical external-cavity surface-emitting lasers (VECSELs), can provide near diffraction-limited, high-quality Gaussian beams and are scalable in output power. Free space resonators also allow the insertion of the birefringent filter and the etalon to enforce single-frequency operation. In addition, the emission wavelengths of OPSLs are tailorable through bandgap engineering. These advantages above make OPSL a strong candidate of laser sources for spectroscopic applications including atomic spectroscopy as well as optical lattice clocks. In this research, a single-frequency laser source with high power is demonstrated by applying the injection-locking technique on OPSLs for the first time. The behaviors of the injection-locked OPSL are studied by varying parameters such as output coupling, injection wavelengths and injection power. It was found that the best injection wavelength is by approximately 2 nm shorter than the free-running slave laser at any given pump power. Below the lasing threshold for free-running operation, the laser starts the stimulated emission process as soon as it is pumped, working as a resonant amplifier. With proper parameters, the output power of the injection-locked laser exceeds the output power of its free-running condition. Over 9 W of single-frequency output power at 1015 nm is achieved. The output beam is near-diffraction-limited with Mₓ² = 1.04 and My² = 1.02. By analyzing the surface photoluminescence (PL) and the output performance of the laser, the saturation intensity of OPSLs is estimated to be 100 kW/cm² when the passive loss of 1.4% is assumed. The injection-locked system adds fairly low phase noise to that of the master laser. By measuring the beat note between the master laser and the injection-locked laser, the RMS values of the phase noise are 0.112 rad and 0.081 rad when using the T = 3% and T = 4% output couplers respectively.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/577280 |
| Date | January 2015 |
| Creators | Lai, Yi-Ying |
| Contributors | Kaneda, Yushi, Jones, Ronald Jason, Kaneda, Yushi, Jones, Ronald Jason, Moloney, Jerome V. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Electronic Dissertation |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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