Active Mode-locked Laser With Fiber Bragg Grating
- Paper number
IAC-07-E2.1.01
- Author
Mr. Fernando Martinez, Universidad Politécnica de Valencia, Spain
- Year
2007
- Abstract
In the last years, an exponential increase in the use of optical communications is taking place, both in the field of terrestrial and space communications. One can find the example of SILEX, the ESA project which culminated in June 2005 when the thousandth optical communication was performed successfully between the European Space Agency's geostacionary technology satellite ARTEMIS and the remote sensing SPOT 4 CNES satellite. The great bandwidth of optical communications, as well as their capacity to make commutations in a link in a much faster way than in the electrical domain, suggest a promising future for this technology. Furthermore, in the space field, these communications make the systems and the equipments easier, since for example huge antennas are no longer needed, which also results in a more economical launch of the space shuttles, due to their less mass and volume. One of the most active research areas nowadays in the field of optical communications consists on the generation of short optical pulses, which will serve for electrooptic sampling systems, as sources for soliton transmission systems, as tunable sources for physics measurements, and also for high-bit-rate systems using an external modulator and time-division multiplexed transmission systems. This work will focus on one of the techniques to achieve short optical pulses: a mode-locked laser. In a usual laser, the modes of the cavity do not have any relation among them, and so they will oscillate independently. The idea of a mode-locked laser consists on stablishing a fixed relation between the phases of the modes of the resonant cavity of the laser so that at least a group of those modes are in phase. In this way, the laser is phase-locked or mode-locked: the modes of the laser will periodically all constructively interfere with one another, producing an intense burst or pulse of light. In this experiment in particular, in order to construct the mode-locked laser, and so its cavity, a Reflective Semiconductor Optical Amplifier (RSOA), a piece of fiber and a Fiber Bragg Grating (FBG) will be used. The use of a SOA offers the possibility of producing small, cheap and reliable sources of stable subpicosecond pulses. This paper will present the results of the simulations of this device, as well as an analysis of which parameters (like the ones of the Fiber Bragg Grating, the current injected to the SOA…) are the most appropriated in order to achieve short optical pulses. Measurements in the laboratory and final conclusions will also be submitted.
- Abstract document