Characterization and Stabilization of Opto Power Fiber-Coupled Laser Diode Arrays

D. F. Phillips, G. P. Wong, D. Bear, R. E. Stoner and R. L. Walsworth

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138

Published in Review of Scientific Instruments:vol. 70, p.2905, July, 1999

Abstract:

We have characterized the spectra and performance of an ensemble of eleven fiber-coupled laser diode arrays (LDAs) manufactured by Opto Power Inc. These high-power LDAs operate near 795 nm and are of a type commonly used for spin-exchange optical pumping of noble gases. We find the Opto Power LDAs to vary significantly in output power, spectral width, and other important characteristics, in a manner not correlated with age, operating lifetime, or information supplied by the manufacturer. In addition we have developed a two-loop feedback technique for use with LDAs that stabilizes the Rb magnetization in an optical pumping cell to better than one part in a thousand.

Measured properties of the ensemble of studied LDAs. (Starred entries were not measured.)

$$\frac{\partial \lambda}{\partial\mathrm{T}} \frac{\partial \mathrm{P}}{\partial\mathrm{T}} \frac{\partial \lambda}{\partial\mathrm{I}} \frac{\partial \mathrm{P}}{\partial\mathrm{I}}$$ laser Opto Power age operating total power linewidth

$${}^\circ {}^\circ$$ number months hours (watts) (nm/A) (W/A) (nm)

1 P204 28 7578 13.8 0.25 -0.30 0.23 0.47 1.8

2 P205 28 1083 10.6 0.19 -0.10 0.25 0.33 2.0

3 P207 26 728 11.1 0.34 -0.31 0.18 0.39 1.3

4 P208 28 6841 9.0 0.36 -0.22 0.30 0.43 1.5

5 P216 25 * 13.9 0.41 -0.36 0.29 0.68 1.0

6 P217 25 141 13.4 0.35 -0.24 0.32 0.38 1.7

7 P218 25 1461 * 0.38 -0.22 0.42 0.29 3.1

8 P219 25 47 13.0 0.34 -0.29 0.34 0.53 4.6

9 P238 20 555 12.1 0.24 -0.10 0.30 0.24 1.3

10 P361 10 14.9 0.20 -0.43 0.18 0.60 1.3

11 P368 6 * 13.7 0.32 -0.15 0.28 0.75 1.5

Avg 21 2049 12.6 0.31 -0.25 0.28 0.46 1.9