Title

Generation and detection of coherent pulse trains in periodically poled Lithium niobate through optical parametric amplification

Date of Award

2011

Degree Name

M.S. in Electro-Optics

Advisor/Chair

Advisor: Peter E. Powers

Abstract

This work reports on the generation, modulation, and detection of temporally coherent pulses in periodically-poled lithium niobate (PPLN) configured as an optical parametric amplifier (OPA). The OPA was pumped at 1 µm, by a 10 kHz, 1 ns, Nd:YAG laser. The cw seeding sources for the OPA were two separate 1550 nm lasers. One source had a short coherence length of .3 km, the other a long coherence length of 95 km. The generated pulse trains where phase modulated by using a set of mirrors on a single axis motorized stage. A 10 km fiber optic delay line was used to simulate free space propagation. A homodyne, coherent optical detection system, utilizing the in-phase and quadrature components of the circularly polarized local oscillator, was built to detect the amplitude and phase modulated pulse trains. We report the detection of the modulated signal for the long coherence length source and the loss of the modulated signal for the short coherence length source, demonstrating that the OPA process can transfer the temporal coherence (or coherence length) of the input signal to the pulse-amplified signal.

Keywords

Optical amplifiers Testing, Coherence (Optics) Testing, Lithium niobate Optical properties

Rights Statement

Copyright 2011, author

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