Widely tunable laser

1. A tunable laser comprising a wavelength filter having an optical path length and a plurality of external cavity modes and, an external cavity optical path length adjustment mechanism coupled to the wavelength filter for varying the optical path length of the wavelength filter so as to select a single external cavity mode from the plurality of external cavity modes, the optical path length adjustment mechanism being substantially independently operable with respect to the wavelength filter, and an electromechanical actuator coupled to each of the wavelength filter and the cavity length adjustment mechanism and control means coupled to each electromechanical actuator for permitting substantially independent adjustment of the wavelength filter and the cavity length adjustment mechanism.

2. The tunable laser of claim 1 further comprising wherein at least one of the electromechanical actuators is a micro-dimensioned actuator coupled to at least one of the wavelength filter and the optical path length adjustment mechanism.

3. The tunable laser of claim 1 further comprising wherein at least one of the electromechanical actuator is a micro-machined actuator coupled to at least one of the wavelength filter and the optical path length adjustment mechanism.

4. A tunable laser apparatus comprising an optical source means for providing light along an optical path, wavelength tuning means in the optical path and having a tuning range and being configured to feed light of a selected wavelength back to the optical source means, microelectromechanical actuation means coupled to the wavelength tuning means for positionally adjusting the wavelength tuning means so as to select the wavelength of the light being fed back to the optical source means and cavity length adjustment means coupled to the wavelength tuning means for controlling the phase of the light being fed back to the optical source means, the wavelength tuning means and the cavity length adjustment means being configured to allow independent adjustment of the wavelength tuning means and the cavity length adjustment mechanism during the tuning.

5. A tunable laser apparatus comprising an optical source means for providing light along an optical path, wavelength tuning means in the optical path having a tuning range and being configured to feed light of a selected wavelength back to the optical source means, microelectromechanical actuation means coupled to the wavelength tuning means for positionally adjusting the wavelength tuning means so as to select the wavelength of light being fed back to the optical source means and to maintain approximately constant phase of the light being fed back to the optical source means over the tuning range of the wavelength tuning means, cavity length adjustment means coupled to the wavelength tuning means for providing additional control of the phase of the light being fed back to the optical source means, and control means coupled to the microelectromechanical actuation means and the cavity length adjustment means for allowing substantially independent adjustment of the microelectromechanical actuation means and the cavity length adjustment mechanism during tuning.

6. A tunable laser comprising a wavelength filter having an optical path length and a plurality of external cavity modes, an external cavity optical path length adjustment mechanism coupled to the wavelength filter for varying the optical path length of the wavelength filter so as to select a single external cavity mode from the plurality of external cavity modes, the optical path length adjustment mechanism being substantially independently operable with respect to the wavelength filter, and a micro-dimensioned actuator coupled to at least one of the wavelength filter and the optical path length adjustment mechanism.

7. A tunable laser comprising a wavelength filter having an optical path length and a plurality of external cavity modes, an external cavity optical path length adjustment mechanism coupled to the wavelength filter for varying the optical path length of the wavelength filter so as to select a single external cavity mode from the plurality of external cavity modes, the optical path length adjustment mechanism being substantially independently operable with respect to the wavelength filter, and a micro-machined actuator coupled to at least one of the wavelength filter and the optical path length adjustment mechanism.