Vince Dominic

Electro-optic spectral tuning in a continuous-wave, asymmetric-duty-cycle, periodically poled LiNbO(3) optical parametric oscillator.

We demonstrate electro-optic spectral tuning in a continuous-wave periodically poled LiNbO(3) (PPLN) optical parametric oscillator (OPO). We achieve 8.91 cm(-1) of rapid spectral tuning, with a linear tuning rate of 2.89 cm(-1) /(kV/mm), by applying electric fields up to +/-1.5 kV/mm across the crystal while it is operating within the OPO. Intentionally poling the PPLN crystal with an asymmetric domain structure enables tuning, and numerical predictions closely match the experimental observations. The tuning is considerably larger than the typical operational bandwidth of the OPO, indicating that we are in fact shifting the gain curve of the PPLN crystal.

Large-scale photonic integrated circuits for long-haul transmission and switching

Feature Issue on Nanoscale Integrated Photonics for Optical Networks Dense wavelength division multiplexed (DWDM) large-scale, single-chip transmitter and receiver photonic integrated circuits (PICs), each capable of operating at 100 Gbits/s, have been deployed in the field since the end of 2004. These highly integrated InP chips have significantly changed the economics of long-haul optical transport networks. First, a review of the ten-channel, 100 Gbits/s PIC is presented. Then two extensions of the technology are demonstrated; first is wide temperature, coolerless operation of the 100 Gbits/s PIC, and second is a single integrated chip with 40 channels operating at 40 Gbits/s, capable of an aggregate data rate of 1.6 Tbits/s.

Periodically poled lithium niobate monolithic nanosecond optical parametric oscillators and generators

We fabricated and characterized periodically poled lithium niobate monolithic optical parametric oscillators (OPOs) and generators. The compact monolithic devices were trivial to align and operate and provided widely tunable, nearly diffraction-limited, stable output pulses. Low thresholds and high conversion efficiencies were obtained when the devices were pumped with 3.5-ns 1.064-mum pulses. In addition, the monolithic OPO devices exhibited broad tuning by crystal rotation through noncollinear phase matching. The bandwidth-broadening effects exhibited in the noncollinear phase-matching geometry were measured and explained.

DIFFUSION-BONDED STACKS OF PERIODICALLY POLED LITHIUM NIOBATE

We constructed diffusion-bonded stacks of periodically poled lithium niobate (PPLN). Such crystals combine the advantages of planar processing used to make PPLN wafers with the power-handling capability of large apertures. We demonstrated an optical parametric oscillator that uses a 3-mm-thick diffusion-bonded stack consisting of three 1-mm-thick PPLN crystals.

110 W fiber laser

We demonstrate a Yb-doped double-clad fiber laser with record average power output of >110 W cw in a single spatial mode beam. The conversion efficiency was /spl sim/58% with respect to the incident pump power.

Real-time visualization of domain formation in periodically poled lithium niobate

We present video footage demonstrating real-time visualization of domain formation in periodically-poled lithium niobate (PPLN). This in-situ, non-destructive technique provides important visual information concerning the global quality and dynamics of domain patterning during the fabrication of PPLN.

Large-Scale Photonic Integrated Circuit Transmitters with Monolithically Integrated Semiconductor Optical Amplifiers

We have successfully demonstrated large-scale photonic integrated circuit (LS-PIC) transmitters with monolithically integrated semiconductor optical amplifiers. Data is presented for for 10 channel devices operating at 10 and 40 Gb/sec.

Growth rate of second-harmonic generation in glass.

We study the growth rate of the light-induced second-order nonlinearity in germanium-doped optical fiber preforms. We seed the glass with both infrared light and green light (Nd:YAG and doubled Nd:YAG) to create the second-order nonlinearity and measure its formation rate while varying the intensity of either the fundamental or the second-harmonic seeding beams. We find that the formation rate varies as a power law of the intensities, but with an exponent larger than predicted by recent models.

Aperture scaling effects with monolithic periodically poled lithium niobate optical parametric oscillators and generators.

We used elliptical beams to demonstrate aperture scaling effects in nanosecond single-grating and multigrating periodically poled lithium niobate (PPLN) monolithic optical parametric oscillators and generators. Increasing the cavity Fresnel number in single-grating crystals broadened both the beam divergence and the spectral bandwidth. Both effects are explained in terms of the phase-matching geometry. These effects are suppressed when a multigrating PPLN crystal is used because the individual gratings provide small effective subapertures. A flood-pumped multigrating optical parametric generator displayed a low output beam divergence and contained 19 pairs of signal and idler frequencies.

Spatial shape of the dc electric field produced by intense light in glass.

A light beam and its second harmonic can create a semipermanent dc electric field inside glass. This dc electric field is responsible for the unexpected production of second-harmonic light in the glass. We determine the transverse spatial shape of this photoinduced dc field inside a bulk sample of germanium-doped fused-silica glass.