Thin film emitter-absorber apparatus and methods
Methods and apparatus for providing a tunable absorption-emission band in a wavelength selective device are disclosed. A device for selectively absorbing incident electromagnetic radiation includes an electrically conductive surface layer including an arrangement of multiple surface elements. The surface layer is disposed at a nonzero height above a continuous electrically conductive layer. An electrically isolating intermediate layer defines a first surface that is in communication with the electrically conductive surface layer. The continuous electrically conductive backing layer is provided in communication with a second surface of the electrically isolating intermediate layer. When combined with an infrared source, the wavelength selective device emits infrared radiation in at least one narrow band determined by a resonance of the device. In some embodiments, the device includes a control feature that allows the resonance to be selectively modified. The device has broad applications including gas detection devices and infrared imaging.
1. A tunable optoelectronic device having at least one absorption emission resonance comprising:
two or more layers, each layer having a controllable property, wherein the two or more layers comprise at least a first layer having a property of being electrically insulating and a second layer having a property of being electrically conductive;
a plurality of discrete surface features on at least one of the two or more layers, the plurality of discrete surface features being arranged such that the at least one absorption emission resonance is established; and
a means for changing the controllable property of at least one of the two or more layers wherein a property of the at least one absorption emission resonance depends on the controllable property changed by said means.
2. The device of claim 1 , wherein said means comprises a tuner which changes the controllable property of the at least one of the two or more layers to adjust the property of the at least one absorption emission resonance.
3. The device of claim 2 , wherein the controllable property of the at least one of the two or more layers changed comprises conductivity.
4. The device of claim 3 , wherein the tuner changes the chemical environment of the device to change the controllable property of the at least one of the two or more layers.
5. The device of claim 4 , wherein the tuner changes the pH of the chemical environment of the device to change the controllable property of the at least one of the two or more layers.
6. The device of claim 5 , wherein the tuner comprises a delivery unit which delivers an acid or base vapor to change the pH of the chemical environment of the device.
7. The device of claim 1 , further comprising an over layer.
8. The device of claim 7 , wherein the over layer comprises a polyaniline layer.
9. The device of claim 1 , wherein at least one of the two or more layers comprises a polyaniline layer.
10. The device of claim 9 or 8 , wherein the controllable property of the polyaniline layer is changed by the means.
11. The device of claim 1 , wherein the means changes the property of the first layer of being electrically insulating.
12. The device of claim 1 , wherein the means changes the property of the second layer of being electrically conductive.