External cavity laser with flexure tuning element
AssigneeMitutoyo Corporation
InventorDavid Sesko
Life of this patent
Estimating the term…
Abstract
An external cavity diode laser may have an output wavelength that is tuned by an end mirror mounted on an element having a flexure hinge. The flexure hinge may be designed to exhibit a stationary pivot point over a desired tuning range, and may allow the external cavity to be tuned without the laser hopping between longitudinal modes. Chromatic dispersion of the laser medium may be accommodated by adjusting a distance between a laser diode and a grating included within the external cavity. The position may be adjusted to find an operating configuration which allows mode-hop-free tuning over the entire desired tuning range.
Claims18
An external cavity laser, comprising:
- a laser radiation source that includes a gain medium and that outputs a collimated beam of radiation;
- a grating element that diffracts the beam of radiation;
- a flexure hinge;
- and
- a tuning mirror mounted to pivot about a hinge axis of the flexure hinge, the tuning mirror reflecting the diffracted radiation beam back to the laser radiation source,
- wherein the grating element defines a first plane, the tuning mirror defines a second plane, and the hinge axis substantially corresponds to the intersection of the first and second planes.
A method for adjusting an external cavity laser to accommodate at least the effects of chromatic dispersion, in order to provide mode-hop-free tuning over a desired tuning range, the method comprising:
- activating an actuator coupled to tuning mirror of the external cavity laser, in order to pivot the tuning mirror about a hinge axis of a flexure hinge such that the external cavity laser scans over a desired tuning range;
- monitoring an output power of the external cavity laser over the desired tuning range;
- adjusting an adjustment mechanism that alters a distance between a laser radiation source and a grating element of the external cavity laser based on the monitored output power, such that mode-hop-free tuning is provided over the desired tuning range.
A method for accommodating at least chromatic dispersion effects to improve a mode-hop-free tuning range of an external cavity laser, comprising:
- measuring an output power of the external cavity laser as a function of tuning of an output wavelength of the external cavity laser;
- adjusting a distance between a laser radiation source and a diffractive element of the external cavity laser;
- and
- remeasuring the output power as a function of tuning of the output wavelength.
Dependencies are inferred from the claim text.