Patent ID: 7382032

Claim:
A terahertz (THz) frequency radiation source to emit THz frequency radiation in a narrow wavelength band within a wavelength range of about 3 μm to 3000 μm comprising: a broad bandwidth THz frequency emitter to generate broad bandwidth THz frequency radiation in an emitted wavelength band within the wavelength range, the emitted wavelength band having; a mid-band wavelength within the emitted wavelength band; and an emitted bandwidth greater than or equal to about 0.01 times the mid-band wavelength; a first planar waveguide optically coupled to the broad bandwidth THz frequency emitter to transmit the broad bandwidth THz frequency radiation; a disk resonator evanescently coupled to the first planar waveguide with a resonance wavelength band within the emitted wavelength band, the resonance wavelength band having a resonance wavelength bandwidth of less than or equal to about 0.25 times the emitted bandwidth; and a second planar waveguide evanescently coupled to the disk resonator to transmit THz frequency radiation in the narrow wavelength band, the narrow wavelength band being substantially equal to the resonance wavelength band of the disk resonator.