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Full-Text Articles in Physics
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael Salisbury, Paul Mcmanamon, Bradley Duncan
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael Salisbury, Paul Mcmanamon, Bradley Duncan
Bradley D. Duncan
In an effort to increase achievable postdetection signal-tonoise ratios (SNRs) of continuous-wave, 1-gm all-solid-state ladar systems, a prototype rare-earth-doped optical-fiber amplifier has been included in the optical return signal path of both a heterodyne and a directdetection ladar system. We provide numerical predictions for SNR increases according to our previously developed theory. We also detail our experimental efforts and provide the results of SNR measurements for four distinct cases: direct ladar detection with and without a fiber amplifier, and heterodyne ladar detection with and without a fiber amplifier. Experimentally measured increases in SNRs for ladar systems incorporating an optical-fiber amplifier …
Mode-Division Multiplexed Transmission In Few-Mode Fibers, Neng Bai
Mode-Division Multiplexed Transmission In Few-Mode Fibers, Neng Bai
Electronic Theses and Dissertations
As a promising candidate to break the single-mode fiber capacity limit, mode-division multiplexing (MDM) explores the spatial dimension to increase transmission capacity in fiberoptic communication. Two linear impairments, namely loss and multimode interference, present fundamental challenges to implementing MDM. In this dissertation, techniques to resolve these two issues are presented. To de-multiplex signals subject to multimode interference in MDM, Multiple-InputMultiple-Output (MIMO) processing using adaptive frequency-domain equalization (FDE) is proposed and investigated. Both simulations and experiments validate that FDE can reduce the algorithmic complexity significantly in comparison with the conventional time-domain equalization (TDE) while achieving similar performance as TDE. To further …
Peak Power Scaling Of Nanosecond Pulses In Thulium Based Fiber Lasers, Christian Gaida
Peak Power Scaling Of Nanosecond Pulses In Thulium Based Fiber Lasers, Christian Gaida
Electronic Theses and Dissertations
Thulium based fiber lasers represent a promising alternative for pulse energy scaling and high peak power generation with ytterbium based systems at 1µm. Advantages of thulium arise from the operation at longer wavelengths and a large gain bandwidth (1.8-2.1µm). Nonlinear effects, such as self phase modulation, stimulated Raman scattering and stimulated Brillouin scattering generally limit peak power scaling in fiber lasers. The longer wavelength of thulium fiber lasers and large mode field areas can significantly increase the nonlinear thresholds. Compared to 1µm systems, thulium fiber lasers enable single mode guidance for two times larger mode field diameter in step index …
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan
Optical-Fiber Preamplifiers For Ladar Detection And Associated Measurements For Improving The Signal-To-Noise Ratio, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan
Electro-Optics and Photonics Faculty Publications
In an effort to increase achievable postdetection signal-tonoise ratios (SNRs) of continuous-wave, 1-gm all-solid-state ladar systems, a prototype rare-earth-doped optical-fiber amplifier has been included in the optical return signal path of both a heterodyne and a directdetection ladar system. We provide numerical predictions for SNR increases according to our previously developed theory. We also detail our experimental efforts and provide the results of SNR measurements for four distinct cases: direct ladar detection with and without a fiber amplifier, and heterodyne ladar detection with and without a fiber amplifier. Experimentally measured increases in SNRs for ladar systems incorporating an optical-fiber amplifier …