Martin R. Amersfoort

Multiwavelength DFB laser arrays with integrated combiner and optical amplifier for WDM optical networks

In this paper, we describe the design, fabrication and performance of multiwavelength DFB laser arrays with integrated combiner and optical amplifier built for wavelength-division-multiplexed (WDM) optical networks. The goal is to reduce the per-wavelength transmitter cost in both initial procurement and subsequent operation. Using photonic integration, we have addressed and resolved several important issues related to laser arrays such as wavelength accuracy, output power, high-speed modulation and optical packaging. State of the art results have been obtained. By the use of wavelength redundancy and proximity effect, wavelength deviations of /spl plusmn/0.2 nm or less from the designated eight-wavelength comb have been achieved with high yield. Simultaneous operation of ten wavelengths has also been demonstrated. In spite of the inherent splitting loss of 13 dB, high-output powers of about -13 and 0.5 dBm per wavelength have been measured, under simultaneous operation, into a single-mode fiber (SMF) without and with on-chip optical amplification, respectively. The DFB laser has a 3-dB bandwidth of 9 GHz. A 2.5-Gb/s (OC-48) error-free transmission through 120 km conventional SMF has been demonstrated under single channel operation. The electrical crosstalk from neighboring channels cause negligible degradation to the eye diagram and the bit-error-rate (BER) curve at a bit rate of 2.5 Gb/s. The optical crosstalk due to four-wave mixing and cross-gain modulation (XGM) of the semiconductor optical amplifier (SOA) is also characterized. The impact of this integrated laser array on WDM optical networks is assessed in the conclusion.

InP-based multiwavelength laser arrays with integrated combiners for WDM systems

In the Optical Network Technology Consortium, we have improved the design and fabrication of InP multiwavelength laser arrays with integrated combiners for the opical transmitters of WDM network access modules. Here we report our recent progress.

Fabrication of InP‐based wavelength division multiplexing arrayed waveguide filters using chemically assisted ion beam etching

Chemically assisted ion beam etching using Cl2 has been used to fabricate InP‐based arrayed waveguide filters that demonstrate full polarization independence and excellent performance characteristics. The process is carried out at elevated temperatures of approximately 250 °C to avoid difficulties associated with the low volatility of indium chlorides at lower temperatures. Optimization of the process for smooth, vertical etching is discussed. InP regrowth is successfully carried out on the etched InGaAsP guides, and measurements of the fabricated devices are presented. The adaptation of the process for angled etching is also demonstrated.

High performance polarization-independent WDM filtering using an InP reflective arrayed waveguide grating

Summary form only given. We report a high-performance polarization-independent InP arrayed waveguide grating (AWG) filter employing a compact reflective geometry. Here, we show that square-core AWGs may be realized in a reflection geometry, and still provide high quality filtering. Successful use of a reflective AWG geometry will permit advanced AWG-based components to be made with smaller die-sizes.

Performance study of a 10-wavelength DFB laser array with integrated electroabsorption modulators

We report the performance of the 10-wavelength DFB laser array with small wavelength dependence of output power, extinction ratio, frequency response and chirp parameter. The active layer consists of six strain compensated quantum wells grown on top of the modulator waveguide layer. Over a wavelength span of 15 nm, the average power into a single mode fiber varies from -3 to 0 dBm (@80 mA), with better than -12 dB (@2 V) extinction ratio, a bandwidth of 5 GHz and chirp parameter less than 1.

Monolithic multiwavelength lasers for WDM lightwave systems

We review the progress of multiwavelength DFB laser arrays made for multiwavelength optical networks. The goal is to reduce the per-wavelength transmitter cost in manufacturing and network element control. Using photonic integration, we have addressed and resolved several important issues related to laser arrays such as wavelength accuracy, output power and optical packaging. State of the art results are summarized and its impact on the multiwavelength optical network is assessed.

Advances in monolithic InP grating-based WDM components

This paper reviews the state-of-the-art of monolithic integration of InP grating-based WDM components. We will discuss the two basic types of InP integrated wavelength demultiplexers: the etched reflection grating spectrograph and the phased-array demultiplexer. They will be compared in terms of their performance and ease of fabrication. Current trends and examples of integration with active components will be presented. In addition, the crucial issue of the wavelength precision of these devices will be addressed.