Skip to main content

Enhanced Performance Lasers for Optical Transmitters

Objective

The objectives of this project are to establish improved laser performance, laser transmitter and amplifier designs for the IBC by exploiting new materials technologies combined with new fabrication methods, novel device designs and new module assemblies. The aim is to identify in conjunction with related RACE projects, which components critically influence systems architectures and to provide prototypes of advanced components for systems experiments.
The objectives of this project are to establish improved laser performance, laser transmitter and amplifier designs for the integrated broadband communications (IBC) by exploiting new materials technologies combined with new fabrication methods, novel device designs and new module assemblies. The aim is to identify which components critically influence systems architectures and to provide prototypes of advanced components for systems experiments.

Using advanced materials growth technology quantum well material, strained layer superlattices and structures based on alternative alloys are fabricated. These materials offer potential improvements of modulation bandwidth and reduction of laser linewidth. The materials and new fabrication methods are used for fabrication of transmitters of novel structures, leading to higher power and enhanced tuneability. Possible reduction of feedback sensitivity is addressed.

The major achievements of the project are:
gallium indium aluminium arsenide (phosphorus free) multiquantum well (MQW) and distributed feedback (DFB) lasers fabricated;
quantum well DFB lasers with combined high power (over 50mW) and narrow linewidth (under 1MHz) fabricated;
strained layer quantum well amplifiers with combined high gain and high saturation power fabricated;
identification of grating structures with low spatial hole burning;
properties of gain coupled DFB lasers clarified theoretically;
gain coupled DFB lasers with high single mode yield and narrow linewidth demonstated experimentally;
multisection distributed Bragg reflector (DBR) lasers with 8.4 nm spectral coverage fabricated;
DFB lasers for 10 Gbit/s operation, including prototype modules fabricated;
lasers used in systems experiments by other RACE projects.
Technical Approach

Using inputs from system driven RACE projects, transmitter characteristics which are considered critical will be identified. The project will establish to what extent enhanced transmitter performance will lead to substantial improvements of system performance.

Using advanced materials growth technology quantum well material, strained layer super-lattices and structures based on alternative alloys will be fabricated. These materials offer potential improvements of modulation bandwidth and reduction of laser line-width. The materials and new fabrication methods will also be used for fabrication of transmitters of novel structures, leading to higher power and enhanced tuneability. Possible reduction of feedback sensitivity will also be addressed.

Key Issues
The key issues for the project are the achievement of: high power output; narrow line-width; wide tuning range; high speed modulation; enhanced reflection tolerance.

Achievements
The major achievements of the project are:

. GaInAlAs (phosphorus-free) MQW and DFB lasers fabricated
. quantum well DFB with combined high power (over 50mW) and narrow linewidth (under 1MHz)
. strained layer quantum well amplifiers with combined high gain and high saturation power
. identification of grating structures with low spatial hole burning
. properties of gain coupled DFB lasers clarified theoretically
. gain coupled DFB lasers with high single mode yield and narrow linewidth demonstrated experimentally.
. multi-section DBR lasers with 8.4 nm spectral coverage.
. DFB lasers for 10 Gbit/s operation, including prototype modules
. lasers used in systems experiments by other RACE projects.

50 papers have been published, three accepted, one under review, total 54 (all in optical communications).

Expected Impact
The enhanced performance will have a significant impact on systems, allowing:

. increase of the number of channels per transmitter
. increase of the number of subscribers served per transmitter
. wider tuning range in coherent multi-channel (CMC) systems
. higher data rate
. reduced component costs
. wider choice of systems architectures.

Coordinator

GEC Marconi Materials Technology Ltd
Address
Caswell
NN12 8EQ Towcester
United Kingdom

Participants (3)

IMEC vzw
Belgium
Philips BV
Netherlands
SIEMENS AG
Germany
Address
Wittelsbacher Platz 2