Frequency modulated laser with high modulation bandwidth
AssigneeHRL Laboratories, LLC
InventorRobert R. Hayes
Life of this patent
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Abstract
A frequency modulated laser comprises a laser cavity in which the gain section of the laser cavity is imbedded within a phase modulation section of the cavity. The laser cavity further comprises electrically-sensitive material, so that an electric field applied across the laser cavity changes the index of refraction within the laser cavity according to the magnitude of the change in the electric field. Uniformly and simultaneously changing the index of refraction along the laser cavity length modulates the frequency of the laser light produced within the laser cavity. The upper bound of the frequency modulation is limited by the propagation time for the electric field to cross the laser cavity.
Claims23
A frequency-modulated laser comprising:
- a laser cavity comprising electrically-sensitive material, said laser cavity having a length dimension and a width dimension, and said laser cavity producing laser light propagating substantially parallel to the length dimension of the laser cavity;
- and
- means for applying a uniform electric field across said laser cavity, said electric field propagating in a direction substantially perpendicular to the direction of propagation of laser light within the laser cavity and having substantially the same intensity along the length dimension of the laser cavity at any one point in time.
A method for frequency modulating a laser light signal with an electrical signal, said method comprising the steps of:
- providing a laser cavity with a length and width, the laser cavity providing a lasing condition;
- producing laser light within the laser cavity, the laser light propagating in a direction substantially parallel to the length dimension of the laser cavity;
- maintaining the lasing condition with energy applied to a gain medium within said laser cavity;
- applying the electrical signal to said laser cavity to produce an electric field uniformly and simultaneously changing the index of refraction along the length of the laser cavity in proportion to the amplitude of the electric signal;
- and
- transmitting the laser light out of the laser cavity to provide a frequency-modulated laser light signal.
A frequency-modulated laser comprising:
- a laser cavity comprising electrically-sensitive material having a changeable index of refraction, the laser cavity having longitudinally coincident gain and phase sections, wherein laser light propagates within the laser cavity in a direction substantially parallel to a length dimension of the laser cavity;
- and
- a traveling wave structure disposed to apply a radio frequency field across the laser cavity to change the index of refraction along the length dimension of the laser cavity length substantially simultaneously and substantially uniformly, the radio frequency field propagating in the traveling wave structure in a direction substantially perpendicular to the direction of laser light propagating in the laser cavity.
Dependencies are inferred from the claim text.