Patent ID: 7057250

Claim:
A terahertz (THz) frequency radiation detector to detect a narrow wavelength band of THz frequency radiation within a wavelength range of about 3 μm to 3000 μm, comprising: a broad bandwidth THz frequency radiation detector with a detection wavelength band within the wavelength range, the detection wavelength band having; a shortest detected wavelength within the detection wavelength band; and a detection bandwidth greater than or equal to about 0.01 times the shortest detected wavelength; and a narrow bandwidth THz frequency band wavelength selector coupled to the broad bandwidth THz frequency radiation detector to select and transmit only THz frequency radiation in the narrow wavelength band to the broad bandwidth THz frequency radiation detector, the narrow bandwidth THz frequency band wavelength selector including; a first planar waveguide optically to receive input radiation; a disk resonator evanescently coupled to the first planar waveguide with a resonance wavelength band within the detection wavelength band, the resonance wavelength band having a resonance wavelength bandwidth of less than or equal to about 0.25 times the detection wavelength bandwidth; and a second planar waveguide evanescently coupled to the disk resonator and optically coupled to the broad bandwidth THz frequency radiation detector to transmit the narrow wavelength band of THz frequency radiation from the disk resonator to the broad bandwidth THz frequency radiation detector, the narrow wavelength band being substantially equal to the resonance wavelength band of the disk resonator.