John James Ellis Reid

Type II sum frequency generation in flux and hydrothermally grown KTP at 1.319 and 1.338 mu m

Type-II, noncritically phase-matched, sum-frequency generation by mixing of the 1.319- and 1.338- mu m lines of a Q-switched Nd:YAG laser with their second harmonics is discussed. Results are presented for KTP crystals grown by both the hydrothermal and the flux technique. A temperature-acceptance width-length product of 8.5+or-0.5 degrees C-cm was determined. Type-II critical phase matching at room temperature, for three different propagation/polarization orientations, is also demonstrated. The differences in the angles required for phase matching between crystals grown by the different techniques are quantified.<<ETX>>

10-Gbit/s error-free transmission of 2-ps pulses over a 45-km span using distributed Raman amplification at 1300 nm

Summary form only given. To meet the requirements of upgrading existing optical fiber networks and to considerably extend the potentially useable bandwidth in the low-loss region in optical fibers, broadband, fiber-based amplifiers outside the Er gain window are required. The wavelength flexibility of Raman fiber amplifiers make them very attractive for integration in current and future systems. Here we report the results of 10-Gbit/s, 2-ps transmission at 1300 nm using distributed Raman amplification. Almost no penalty has been observed for the experimental situation where the system loss was directly compensated by the Raman gain and where an excess gain of +8 dB was achieved.

114 km, repeaterless, 10 Gbit/s transmission at 1310 nm using an RZ data format

There is an increasing interest in 1310-nm optical amplification as more than 50 million km of standard single-mode fiber (SSMF) has been installed worldwide. Consistent developments in the field of 1310-nm optical amplification have resulted in high-gain (>30 dB) polarization-insensitive semiconductor optical amplifiers (SOAs) for optical pre-amplification and high saturation output power (14 dBm) SOA boosters. These devices were implemented in a repeaterless transmission system. Here a DFB laser diode operating at 1310 nm was gain switched at 10 GHz to produce return-to-zero (RZ) pulses of 30 ps at FWHM that were subsequently de-chirped and compressed to 18 ps at FWHM using 4.4 km of dispersion-shifted fiber. After boosting the 10-GHz pulse train up to 10 dBm, the pulse train was modulated with a 10 Gbit/s, 2/sup 31/-1 pseudorandom bit sequence by the LiNbO/sub 3/ electro-optic modulator with an extinction ratio of 15 dB. Finally, the signal is boosted up to 12 dBm and launched into 114 km of SSMF (zero dispersion at 1309 nm) with a total attenuation of 42.9 dB. The signal at the output of the second booster did not show any pattern effects. A 400-mA bias current was applied to each of the two boosters. The boosters exhibited a fiber-to-fiber gain of 13.6 dB and 15.4 dB and a 3-dB saturation output power of 16 dBm and 13 dBm, respectively.

Performance of Cascaded 1300 nm QW Laser Amplifiers in 10 Gbit/s Long Haul NRZ Transmission

At present more than 55 million kilometers of the standard type single mode fibre (SMF) have been installed. Showing zero dispersion at a wavelength of about 1310 nm, SMF offers great potential when the bitrate × distance product is considered, if it were not for the attenuation of the fibre. Therefore, design of very high speed digital transmission systems in the 1300 nm region is very attractive. Recently significant progress has been achieved in the development of Quantum Well Laser Amplifiers (QWLAs) with the use of suitably strained Quantum Well materials [1,2]. Although a few promising results have been published using these amplifiers [3, 4], especially a 10 Gbit/s transmission over 200 km, representing a record NRZ transmission capacity using Semiconductor Laser Amplifiers (SLAs), the study on the performance of cascaded QWLAs in high bitrate long haul transmission systems is far from completed yet.

Progress in high-speed 130-nm optical communication

The current status of high speed 1300 nm optical transmission will be reviewed in this paper. In particular the activities within the collaborative ACTS Upgrade project will be presented comprising 10 Gbit/s field trials, an experimental 40 Gbit/s OTDM laboratory test bed and initial work on 40 Gbit/s WDM transmission.