Jonathan R. Kurz

Highly efficient second-harmonic generation in buried waveguides formed by annealed and reverse proton exchange in periodically poled lithium niobate

Efficient three-wave mixing devices have numerous applications, including wavelength conversion, dispersion compensation, and all-optical switching. Second-harmonic generation (SHG) is a useful diagnostic for near-degenerate operation of these devices. With buried waveguides formed in periodically poled lithium niobate by annealed and reverse proton exchange, we demonstrate what is believed to be the highest normalized conversion efficiency (150%/W cm(2)) for SHG in the 1550-nm communications band reported to date.

Periodically poled lithium niobate waveguide sum-frequency generator for efficient single-photon detection at communication wavelengths

We present a device to facilitate single-photon detection at communication wavelengths based on continuous-wave sum-frequency generation with an upconversion efficiency exceeding 90%. Sum-frequency generation in a periodically poled lithium niobate waveguide is used to upconvert signal photons to the near infrared, where detection can be performed efficiently by use of silicon avalanche photodiodes.

Observation of 99% pump depletion in single-pass second-harmonic generation in a periodically poled lithium niobate waveguide

We report 99% pump depletion in single-pass second-harmonic generation. Quasi-cw pulses at 1550 nm were frequency doubled in an annealed proton-exchanged waveguide formed in periodically poled lithium niobate. Measurements of pump depletion and second-harmonic generation agree with results from numerical integration of the coupled-mode equations that describe the process.

Periodic poling of magnesium-oxide-doped lithium niobate

In this article, poling characteristics and periodic poling of magnesium-oxide-doped lithium niobate (MgLN) are described. Periodic poling was done by the electric field method, with which uniform gratings were produced. The domain wall velocity as a function of poling field was measured and used to determine conditions for self-terminating periodic poling. A computational model for the self-termination method is also discussed here. In the experiment, it was found that thermal history prior to poling has a significant influence on the poling quality.

160-Gb/s OTDM transmission using integrated all-optical MUX/DEMUX with all-channel modulation and demultiplexing

This letter provides the first report of 160-Gb/s optical time-division-multiplexed transmission with all-channel independent modulation and all-channel simultaneous demultiplexing. By using a multiplexer and a demultiplexer based on periodically poled lithium niobate and semiconductor optical amplifier hybrid integrated planar lightwave circuits, 160-km transmission is successfully demonstrated.

Bandwidth and tunability enhancement of wavelength conversion by quasi-phase-matching difference frequency generation

Abstract Bandwidth and tunability enhancement of difference frequency generation (DFG)-based wavelength conversion by introducing various distributing formats of π-phase shifting domains into the quasi-phase-matching (QPM) gratings is demonstrated, and the concise expressions describing the tuning curves in these cases are obtained for the first time. The results show not only the pump and signal bandwidth can be obviously broadened and flattened, but also diverse comblike pump–wavelength tuning curves with controllable channel spacing can be achieved by introducing periodically distributed π-phase shifting domains into the QPM gratings, which would greatly improve the tunability and practibility of DFG-based wavelength converters.

Mode multiplexing in optical frequency mixers

Asymmetric Y junctions allow the development of a new class of optical frequency mixers that utilize higher-order waveguide modes for signal processing. We measure high-contrast (>30 dB) mode sorting in asymmetric Y junctions by use of a novel technique: efficient TM00, TM10, and TM20 mode mixing in a periodically poled lithium niobate waveguide. We also demonstrate an odd-to-even mode wavelength converter capable of spectral inversion without offset or bidirectional wavelength conversion.

Tunable Wavelength Conversion of ps-Pulses Exploiting Cascaded Sum- and Difference Frequency Generation in a PPLN-Fiber Ring Laser

Tunable wavelength conversion of picosecond (ps)-pulses based on cascaded sum- and difference frequency generation is proposed and demonstrated by use of a fiber ring laser incorporating a periodically poled lithium niobate waveguide and two parallel-arranged tunable filters (TFs). The pulsed signal with 40-GHz repetition rate and 1.57-ps pulsewidth is employed. No external pump and control sources are required in the wavelength converter. By properly adjusting two TFs to change the lasing pump and control wavelengths, flexible wavelength conversion from a changeable input signal wavelength to a variable output idler wavelength is achieved

Multichannel wavelength conversion exploiting cascaded second-order nonlinearity in LiNbO 3 waveguides

Ten-channel wavelength conversion is achieved by exploiting cascaded second-order nonlinearity in periodically poled LiNbO/sub 3/ waveguides. No external pump input is required in the converter and conversion efficiency is improved due to the enhancement of pump and signal interaction. Approximate 70-nm conversion bandwidth is realized under pump power less than 25 mW at 1550-nm band.

Squeezing in a LiNbO3 integrated optical waveguide circuit

We report on traveling-wave quadrature squeezing generated in an integrated optical circuit fabricated with periodicallypoled lithium niobate waveguides. The device integrates a secondharmonic-generation stage, waveguide couplers, spatial mode filters, and a degenerate-optical-parametric-amplification stage. The integrationpromises to create a low power, compact, and simple source of wideband squeezed light. -1 dB of squeezing is directly measured using 20 ps pulses with peak powers near 6W.