Jan-Olof Wesström

Design of a widely tunable modulated grating Y-branch laser using the additive Vernier effect for improved super-mode selection

We present the design of a modulated grating Y-branch semiconductor laser containing a splitter and two multi-peak reflectors. High selectivity is achieved using the additive Vernier effect.

10 Gb/s direct modulation of 40 nm tunable modulated-grating Y-branch laser

High speed properties of a directly modulated widely tunable MG-Y laser have been evaluated. Small signal response and 10 Gb/s NRZ modulation were performed within the 40 nm tuning range.

New widely tunable edge-emitting laser diodes at 1.55 μm developed in the European IST-project NEWTON

Widely tunable lasers are generally considered as the transmitters of future WDM optical communications. Electronically tunable edge-emitting laser diodes are of particular interest as they can switch the wavelength in tens of nanoseconds and thus offer great potential for new networking concepts such as optical packet or burst switching, label switching, bandwidth on demand, ... In this paper we discuss new concepts for such widely tunable laser diodes which are studied in the framework of the European IST project NEWTON (NEw Widely Tunable laser diodes for Optical Networks).

On the frequency stability of widely tunable GSCR lasers

The results of the two lifetime studies show that it is certainly possible to achieve high frequency stability for widely tunable grating coupled semiconductor ridge waveguide (GCSR) lasers. Moreover, experimental results show that there is a possibility to enhance the stability further through mode and frequency locking algorithms. The algorithm handles both frequency drift and mode hops and does also ensure that other channels are found with accuracy without switching to the wrong mode.

Narrow linewidth tunable semiconductor laser

A full-C band tunable laser equipped with an air-gap suspended waveguide structure for efficient thermal heater tuning is described. It is shown that the monolithic tunable laser can simultaneously meet the requirements for the output power, side-mode suppression ratio, and spectral linewidth for 16-QAM coherent communication system. Together with an optimized design for the Bragg grating and a reduced optical loss for thermally-tuned un-doped waveguide, a high SMSR of 54.5 dB, an output power of 19 dBm, and 80 kHz linewidth over 103 channels across the C-band were achieved. A possibility for further reduction of the heater tuning power is also discussed.

Progress in integrated widely tunable edge-emitting 1.55 μm laser diodes

We present the progress obtained in recent years on widely tunable edge-emitting lasers at 1.55 μm. We focus on electronically tunable lasers, which can switch the wavelength in tens of nanoseconds and thus offer great potential for new networking concepts such as optical packet/burst switching, label switching, bandwidth on demand,...