High power narrow linewidth discrete mode laser diode integrated with a curved semiconductor optical amplifier emitting at 2051 nm.

We report on a 2.051 μm InGaAs/InP-based discrete mode laser diode monolithically integrated with a curved tapered semiconductor optical amplifier for CO sensing applications. At a heat-sink temperature of 0°C, the laser emits a record InP value of more than 35 mW continuous-wave output power in a single longitudinal mode.

Modulator-free quadrature amplitude modulation signal synthesis.

The ability to generate high-speed on-off-keyed telecommunication signals by directly modulating a semiconductor laser's drive current was one of the most exciting prospective applications of the nascent field of laser technology throughout the 1960s. Three decades of progress led to the commercialization of 2.5 Gbit s(-1)-per-channel submarine fibre optic systems that drove the growth of the internet as a global phenomenon.

Demonstration of amplified data transmission at 2 µm in a low-loss wide bandwidth hollow core photonic bandgap fiber.

The first demonstration of a hollow core photonic bandgap fiber (HC-PBGF) suitable for high-rate data transmission in the 2 µm waveband is presented. The fiber has a record low loss for this wavelength region (4.5 dB/km at 1980 nm) and a >150 nm wide surface-mode-free transmission window at the center of the bandgap.

Dual correlated pumping scheme for phase noise preservation in all-optical wavelength conversion.

We study the effect of transfer of phase noise in different four wave mixing schemes using a coherent phase noise measurement technique. The nature of phase noise transfer from the pump to the generated wavelengths is shown to be independent of the type of phase noise (1 / f or white noise frequency components). We then propose a novel scheme using dual correlated pumps to prevent the increase in phase noise in the conjugate wavelengths.

Wide temperature range 0 < T < 85 °C narrow linewidth discrete mode laser diodes for coherent communications applications.

Cost effective lasers meeting the linewidth requirements for coherent communication systems are a key element in reducing the overall cost of future coherent systems. We report on monolithic devices with linewidths as low as 138 kHz which operate in a narrow linewidth, single wavelength mode with high sidemode suppression ratio over a wide temperature tuning range of -10 °C < T < 110 °C. A linewidth variation of only 23 kHz was measured at a constant emitted power of 4 mW as the device temperature is varied in the range 0 °C < T < 85 °C.

40 nm wavelength tunable gain-switched optical comb source.

A wavelength tunable optical comb is generated based on the gain-switching of an externally seeded Fabry-Pérot laser diode. The comb consists of about eight clearly resolved 10 GHz coherent sidebands within 3 dB spectral envelope peak and is tunable over the entire C-band (1530 to 1570 nm). The optical linewidth of the individual comb tones is measured to be lower than 100 kHz, and the RIN of the individually filtered comb tones (<-120 dB/Hz) is shown to be comparable to the entire unfiltered comb (<-135 dB/Hz).

Implementation of a cost-effective optical comb source in a WDM-PON with 10.7 Gb/s data to each ONU and 50 km reach.

The performance of a cost-effective optical comb source using commercial off the shelf (COTS) components in a WDM passive optical network is demonstrated. Eight comb modes are individually modulated at 10.7 Gb/s and transmitted over 50 km of single mode fiber for downlink transmission.

Phase shift keyed systems based on a gain switched laser transmitter.

Return-to-Zero (RZ) and Non-Return-to-Zero (NRZ) Differential Phase Shift Keyed (DPSK) systems require cheap and optimal transmitters for widespread implementation. The authors report on a gain switched Discrete Mode (DM) laser that can be employed as a cost efficient transmitter in a 10.7 Gb/s RZ DPSK system and compare its performance to that of a gain switched Distributed Feed-Back (DFB) laser.