Systems and methods for adjusting optical path length of an optical path
are provided. The systems and methods can be used to controllably adjust
optical path length in an external cavity laser. A representative optical
path having a first end and a second end comprises a first transparent
refractive element located in the optical path between the first end and
the second end. The transparent refractive element is adjustable to adjust
the optical path length of the optical path without changing the physical
distance between the first end and the second end. A representative method
includes introducing a transparent refractive element into the optical
path and adjusting the transparent refractive element to change the
optical path length without changing the physical distance between the
first end and the second end of the optical path.
