S. Slempkes

10-wavelength 200-GHz channel spacing emitter integrating DBR lasers with a PHASAR on InP for WDM applications

A 10-wavelength 200-GHz channel spacing emitter was realized by monolithically integrating on InP a 10 distributed-Bragg-reflector laser array and a PHASAR used as a 10/spl rarr/1 combiner. The design of a wide-squared spectral bandwidth for the PHASAR as well as the lasers tunability ensure wavelength matching between the PHASAR transmission comb and the laser array comb. The channel spacing accuracy of the source is better than 25 GHz and the rejection is higher than 32 dB for all bias.

Low-damage dry-etched grating on an MQW active layer and dislocation-free InP regrowth for 1.55-/spl mu/m complex-coupled DFB lasers fabrication

A grating dry-etched through the upper wells of a multiquantum-well active layer has been characterized before and after regrowth. TEM observation and carrier lifetime measurements have shown growth-free defects of the epitaxial layers. As a consequence, quasi-100% monomode oscillation on /spl lambda/+1 mode has been achieved on complex-coupled distributed-feedback GaInAsP QW lasers fabricated with such grating.

Agile and fast switching monolithically integrated four wavelength selectable source at 1.55 μm

We demonstrate 4-nm spaced four emitted wavelengths on a single output waveguide in a four channel DBR lasers array monolithically integrated with a 4>1 coupler. Using distributed Bragg reflector tunability, all wavelengths within a 16-nm range can be reached with an accuracy better than 0.2 nm. Wavelength switching time measured at 90% of nominal power is 4 ns.

Novel approach for simple fabrication of high-performance InP-switch matrix based on laser-amplifier gates

We report here on an InP-switch matrix based on laser-amplifier gates with gain- and polarization-insensitive (as low as 1 dB) operation. A novel integration scheme is demonstrated that provides over 10 dB net chip gain for both input polarizations. Fiber-to-fiber operation with gain can moreover be obtained. Design and switching characteristics are detailed.

Multiwavelength grating reflectors for widely tunable laser

We propose a new reflector approach in order to get the reflectivity comb needed in widely tunable lasers. This reflector is realized by holographic exposure of superimposed multiple Bragg gratings. It provides efficient reflectivity with short guide sections (150 /spl mu/m) leading to improved static laser characteristics. This reflector has been successfully included in 20-nm tuning DBR lasers.

A new distributed Bragg reflector laser for improved tuning

We propose a new distributed Bragg reflector laser using the phase variation of the Bragg facet reflectivity to improve the tunability. The modelling yields a 20 nm tuning range corresponding to a 8 nm increase of the classic DBR tunability. Preliminary experimental results confirmed this tuning improvement.<<ETX>>

Simple multiwavelength device fabrication technique using a single-grating holographic exposure

A simple technique, using a single-grating holographic exposure associated with localized selective etching steps, has been developed for multiwavelength device fabrication. Four-wavelength DBR laser arrays with a 5 nm Bragg wavelength spacing have been fabricated for wavelength division multiplexing (WDM) applications with this method. These devices exhibit uniformly low-threshold currents (10-15 mA), high-output powers (15 mW) and wide tunabilities (12 nm), leading to an overall accessible wavelength domain of 28 nm for the array.

Accurate wavelength spacing from absorption-coupled DFB laser arrays

Six-element absorption-coupled distributed-feedback (DFB) arrays have been fabricated by means of holographic lithography. Using a simple current injection scheme in two-section devices, a standard deviation of 0.11 nm from a uniform wavelength channel spacing of 2 nm has been achieved. This value is easily obtained using standard lithography technologies for fabrication, and coarse current control for operation. It allows the use of complex-coupled DPB lasers as sources in photonic integrated circuits.

High speed gain-switched laser as very simple 4/spl times/10 Gbit/s and up to 8/spl times/10 Gbit/s OTDM source

1.55 /spl mu/m DFB lasers based on strain compensated MQW structures with fast dynamics and high chirping effects were fabricated for standard gain-switched pulse emission at 10 GHz. After linear pulse compression to compensate for the chirp, low jitter (<1 ps), -6 ps pulses with extinction ratio compatible with 4/spl times/10 Gbit/s and up to 8/spl times/10 Gbit/s were easily obtained as evidenced from streak camera measurements.