Passive detector structures for imaging systems are provided, which are based on a coefficient of thermal expansion (CTE) framework. With such framework, a CTE-based passive detector structure includes a detector member that is configured to expand or contract in response to thermal heating resulting from photon exposure. The expanding/contracting CTE detector structure is configured to exert mechanical forces on resistor and/or capacitor circuit elements, which are part of an oscillator circuit, to vary the resistance and capacitance of such circuit elements and change a frequency or period of oscillation of an output signal of the oscillator circuit. The change in the frequency or period of oscillation of the output signal of the oscillator circuit is utilized to determine an amount of photon exposure of the CTE-based detector.

Passive detector structures for imaging systems are provided, which are based on a coefficient of thermal expansion (CTE) framework. With such framework, a CTE-based passive detector structure includes a detector member that is configured to expand or contract in response to thermal heating resulting from photon exposure. The expanding/contracting CTE detector structure is configured to exert mechanical forces on resistor and/or capacitor circuit elements, which are part of an oscillator circuit, to vary the resistance and capacitance of such circuit elements and change a frequency or period of oscillation of an output signal of the oscillator circuit. The change in the frequency or period of oscillation of the output signal of the oscillator circuit is utilized to determine an amount of photon exposure of the CTE-based detector.

A resonator includes a piezoelectric plate and interdigitated electrode(s). The interdigitated electrode includes a plurality of conductive strips disposed over a top surface of the piezoelectric plate. A two-dimensional mode of mechanical vibration is excited in a cross sectional plane of the piezoelectric plate in response to an alternating voltage applied through the interdigitated electrode. The two-dimensional mode of mechanical vibration is a cross-sectional Lam mode resonance (CLMR) or a degenerate cross-sectional Lam mode resonance (dCLMR).

A resonator includes a piezoelectric plate and interdigitated electrode(s). The interdigitated electrode includes a plurality of conductive strips disposed over a top surface of the piezoelectric plate. A two-dimensional mode of mechanical vibration is excited in a cross sectional plane of the piezoelectric plate in response to an alternating voltage applied through the interdigitated electrode. The two-dimensional mode of mechanical vibration is a cross-sectional Lam mode resonance (CLMR) or a degenerate cross-sectional Lam mode resonance (dCLMR).

A resonator including a piezoelectric plate and an interdigital electrode is provided. A ratio between a thickness of the plate and a pitch of the interdigital electrode may be from about 0.5 to about 1.5. A radiation detector including a resonator and an absorber layer capable of absorbing at least one of infrared and terahertz radiation is provided. A resonator including a piezoelectric plate and a two-dimensional electrically conductive material is provided.

A resonator including a piezoelectric plate and an interdigital electrode is provided. A ratio between a thickness of the plate and a pitch of the interdigital electrode may be from about 0.5 to about 1.5. A radiation detector including a resonator and an absorber layer capable of absorbing at least one of infrared and terahertz radiation is provided. A resonator including a piezoelectric plate and a two-dimensional electrically conductive material is provided.

A resonator includes a piezoelectric plate and interdigitated electrode(s). The interdigitated electrode includes a plurality of conductive strips disposed over a top surface of the piezoelectric plate. A two-dimensional mode of mechanical vibration is excited in a cross sectional plane of the piezoelectric plate in response to an alternating voltage applied through the interdigitated electrode. The two-dimensional mode of mechanical vibration is a cross-sectional Lam mode resonance (CLMR) or a degenerate cross-sectional Lam mode resonance (dCLMR).

A resonator including a piezoelectric plate and an interdigital electrode is provided. A ratio between a thickness of the plate and a pitch of the interdigital electrode may be from about 0.5 to about 1.5. A radiation detector including a resonator and an absorber layer capable of absorbing at least one of infrared and terahertz radiation is provided. A resonator including a piezoelectric plate and a two-dimensional electrically conductive material is provided.

A resonator including a piezoelectric plate and an interdigital electrode is provided. A ratio between a thickness of the plate and a pitch of the interdigital electrode may be from about 0.5 to about 1.5. A radiation detector including a resonator and an absorber layer capable of absorbing at least one of infrared and terahertz radiation is provided. A resonator including a piezoelectric plate and a two-dimensional electrically conductive material is provided.

Multi-spectrum imaging systems and methods are provided to imaging in multiple spectrums, e.g., thermal IR (infrared) at 4 m and 10 m wavelengths, near-IR, and visible light, all on a same optical centerline. For example, an imaging system includes a first imager and a second imager. The first imager includes an array of thermal IR detectors, wherein the first imager is configured to receive incident photonic radiation and generate a thermal IR image, wherein each thermal IR detector comprises a photon absorber member that is configured to absorb thermal IR photonic radiation from the incident photonic radiation, and reflect remaining photonic radiation in the incident photonic radiation along an optical path of the imaging system. The second imager is disposed in said optical path of the imaging system, wherein the second imager is configured to receive the remaining photonic radiation reflected from the first imager and generate a second image.