Luc Boivin

T-ray tomography

We demonstrate tomographic T-ray imaging, using the timing information present in terahertz (THz) pulses in a reflection geometry. THz pulses are reflected from refractive-index discontinuities inside an object, and the time delays of these pulses are used to determine the positions of the discontinuities along the propagation direction. In this fashion a tomographic image can be constructed.

A 1021 channel WDM system

We demonstrate a WDM system with 1021 independent wavelength channels within the C- and L-bands of the EDFA. All channels carry RZ data at 74 Mb/s and are spaced by only 9.5 GHz. We demonstrate transmission over 60 km of standard single mode fiber with power penalties of less than 1.5 dB. The transmitter uses a single wideband optical source and eight high-speed modulators. With optical demultiplexing and low bandwidth receivers, this system has the potential as a low per-port cost access grade system.

Propagation of highly chirped pulses in fiber-optic communications systems

The propagation of strongly chirped pulses in an amplified fiber-optic communications system is experimentally investigated. Spectral narrowing of the pulses is observed. The narrowing is attributed to interplay between the initial chirp and the nonlinearity in the transmission line. Four-wave mixing (FWM) between wavelength channels is found to be similar to that for unchirped nonreturn-to-zero (NRZ) pulses. Low error rate transmission over 720 km is achieved using these chirped pulses, which are generated by a transmitter based on a mode-locked fiber laser.

A 1021 CHANNEL WDM SYSTEM

Growing demand for bandwidth at distributed locations, such as homes and small businesses, will require systems capable of delivering high bandwidths (>10 Mb/s) at affordable costs. Here, we describe an optical system capable of delivering independent 74 Mb/s streams to a very large number of users (>1000) using a technique with potentially low per-port costs.

RAMAN-NOISE LIMIT ON SQUEEZING IN CONTINUOUS-WAVE FOUR-WAVE MIXING

The continuous-time quantum theory of self-phase modulation (SPM) in lossless, dispersionless, single-mode fiber requires a nonzero response time, to capture the classical SPM limit properly, and an accompanying Raman noise, to ensure commutator preservation. The continuous-wave, four-wave mixing limit of this theory is shown to harbor a Raman-noise limit on fiber-based squeezed-state generation.

206-channel chirped pulse wavelength-division-multiplexed transmitter

vices as well as with new international directions. Bit rates are also compatible with worldwide standards. Digital video, once a challenge in terms of both bit rate and cost, is becoming a commodity item thanks to markets rapidly developing around satellite TV and personal computers. Finally, it is now recognized that the firstcost premium of FTTH compared with other networks vanishes for certain early applications such as rural installations.’ As costs continue to fall, suburban then urban installations will subsequently reach parity. Surprisingly, though, even for suburban applications, Bellcore studies show that FTTH offers annual savings in operating ~os t s possibly large enough to offset today’s premium. The bottom line is that FTTH makes sense to install soon if not now, and manufacturers are responding with new FTTH product development. 1.