TECHNICAL FIELD

Example embodiments relate generally to spectral conditioning systems and, more particularly, relate to dynamic filtering for spectral sensing and emitting systems.

BACKGROUND

Radiant energy sensors and associated sensing and imaging systems have a wide variety of applications. Such systems may be used, for example, to receive and facilitate analyses of radiant energy transmitted though or reflected off of materials or chemicals in an effort to identify the composition of the materials or chemicals. Conventional systems that incorporate interferometers, spectrometers, or other hyperspectral sensors, for example, may be capable of performing such applications, but these systems are expensive, large, heavy, and have high power requirements. As such, conventional systems simply are not feasible for implementation on small remote platforms, such as aerial drones and other unmanned aerial vehicles (UAVs), unmanned terrestrial vehicles such as planetary rovers used in the space program, on board satellites, or the like. Such limitations of conventional systems are particularly problematic for systems that operate in the infrared spectrum and, more specifically, in the mid-wavelength infrared spectrum [i.e., wavelengths from 3 to 8 micrometer (μm)] and the long-wavelength infrared spectrum (i.e., wavelengths from 8 to 15 μm). As such, there is a continued need to develop radiant energy systems and component technologies that can be leveraged by radiant energy systems to increase the breadth of applications where such systems can be used.

BRIEF SUMMARY OF SOME EXAMPLES

According to some example embodiments, an apparatus is provided. The apparatus may include a substrate, a first patterned layer, a second patterned layer, and control circuitry. The first patterned layer may be coupled to the substrate and may include a first pattern. In this regard, the first patterned layer may include a first metasurface. The second patterned layer is disposed separately from the substrate and the first patterned layer, and the second patterned layer may include a second pattern. The second patterned layer may include a second metasurface. The control circuitry may be in communication with the first patterned layer and the second patterned layer. Further, the control circuitry may be configured to control the first patterned layer or the second patterned layer to move the first patterned layer and the second patterned layer into a position such that a gap distance of a gap between the first patterned layer and the second patterned layer is changed to cause a transmittance for radiant energy of a selected wavelength passing through the apparatus to change from a first transmittance value to a second transmittance value.

According to other non-limiting example embodiments, a system includes a radiant energy filter array including a plurality of filter elements arranged in a common plane. The plurality of filter elements may include a first filter element and a second filter element. The system may also include control circuitry in communication with the first filter element and the second filter element. The control circuitry may be configured to control the first filter element the second filter. The system may also include a radiant energy sensor positioned to receive radiant energy passing through the radiant energy filter array. In this regard, the first filter element may include a first microelectromechanical device. The first microelectromechanical device may include a first metasurface and a second metasurface. The first metasurface may be movable towards the second metasurface via an attraction force controlled by the control circuitry to change a transmittance for radiant energy of a first wavelength and controllably pass radiant energy of the first wavelength to the radiant energy sensor. Further, the second filter element may include a second microelectromechanical device. The second microelectromechanical device may include a third metasurface and a fourth metasurface. The third metasurface may be movable towards the fourth metasurface via an attraction force controlled by the control circuitry to change a transmittance for radiant energy of a second wavelength and controllably pass radiant energy of the second wavelength to the radiant energy sensor.

According to additional example embodiments, a method is provided. The method may include providing a substrate and patterning a first metasurface layer onto the substrate. In this regard, the first metasurface layer may include a metal. The method may further include depositing an actuation and anchor member layer onto the first metasurface layer, coating the substrate, the first metasurface layer, and the actuation and anchor member, and depositing a sacrificial gap layer. The method may further include depositing a dielectric spacer layer on the sacrificial gap layer and patterning a second metasurface layer onto the dielectric spacer layer. In this regard, the second metasurface layer may include a metal. The method may further include depositing a dielectric upper beam layer on the second metasurface layer, depositing beam metal on the dielectric upper beam layer, and releasing a microelectromechanical device by removing the sacrificial gap layer.

