Because of their small spectral width and good beam quality, low cost tunable lasers are a key to lower operation and deployement cost of telecommunication networks. They are also used for passive component characterization and spectroscopy.

Here, we propose a tunable Erbium doped ring fiber laser that is continuously tuned by a micro-electro-mechanically actuated Fabry-Perot cavity.

The Fabry-Perot (F-P) cavity is formed by two distributed Bragg mirrors made of alternate vertical layers of silicon and air.
It is tuned by displacing one of the Bragg mirror using a electrostatic comb drive actuator. As voltage is increased between the combs, the suspended comb is attracted toward the fixed one. Then, the lenght of the F-P cavity is reduced and a smaller wavelength is filtered.

One possible application for this MENS actuated filter is for tuning a laser and then for making a tunable fiber laser. By introducing this filter into a ring fiber laser cavity, it results in a quasi-all fiber tunable laser.

This system finds applications in:
- telecommunication networks,
- laser machining,
- bio-sensing

Benefits and Features

Fabry-Perot cavity:
- One single fabrication step
- Tuning range of 73 nm
- 3.5 kHz resonance frequency
- Maximum operation voltage of 15.4V
- Verticality better than 0.5°
- Surface roughness: 26 nm RMS

Laser:
- 26 nm tuning range
- Spectral width: better than 0.03 nm FWHM
- SNR more than 30 dB
- Quasi all fiber laser



Papers and publications available on : http://www.polymtl.ca/mems/publications/index.php