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US 4,395,769 AGranted
Tunable semiconductor laser
AssigneeBell Telephone Laboratories, Incorporated
InventorsTheodoor C. Damen, Michel A. Duguay
Life of this patent
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Abstract
Tunable laser radiation is obtained by pumping a wedge-shaped ultra-short laser cavity with picosecond excitation pulses. Continuous tuning of the laser is achieved by translating either the wedge-shaped laser cavity or the excitation pulses so that different volumes of the laser material are exposed to the excitation pulses. In one embodiment utilizing picosecond laser excitation pulses the wedge-shaped laser cavity is a slightly wedged film of GaAs coated on both sides with dielectric mirrors.
Claims16
A laser which comprises:
- a thin film (1) of semiconductor material disposed between mirrors (2 and 3) and
- excitation means (15 and 16) for producing a population inversion in a predetermined volume of said semiconductor material
- characterized in that
- said thin film has a variation in thickness from a first end to a second end thereof and said excitation means provides high intensity excitation pulses having an ultra-short time duration, the time duration of said excitation pulse being less than or substantially equal to one picosecond, said thickness of said semiconductor material being less than or substantially equal to the distance at which the electron-hole plasma produced by said excitation pulse fills substantially all of said thickness of said material in said time duration, and at least one of said mirrors comprises at least one layer of material having a variation in thickness from a first end to a second end thereof.
1 more element
A laser which comprises:
- a first thin film (17) of semiconductor material having sides which are substantially parallel and a thickness less than or substantially equal to 1 .mu.m, said film being disposed between a first mirror (31) and a second mirror (32), said first and second mirrors being substantially parallel;
- a second thin film (49) of semiconductor material having a variation in thickness from a first end and a second end thereof less than or substantially equal to 1 .mu.m, said second thin film being disposed between said second mirror and a third mirror (33), said third mirror comprises at least one layer of material having a variation in thickness from a first end and a second end thereof;
- and
- excitation means (15 and 16) for producing a population inversion in a predetermined volume of the semiconductor material of said first thin film, said excitation means provides high intensity excitation pulses of time duration less than or substantially equal to 10 picoseconds.
1 more element
Dependencies are inferred from the claim text.