Abstract: Provided is an electro-optic reflective modulator comprising a reflective active material, preferably comprising a reflective organic free radical compound, that reflects a wavelength in a highly reflective state and is reversibly switched to a transparent and low reflectivity state at the wavelength by the application of an electric current. Preferably, the electro-reflective optical modulator is solid state with no moving parts such that the active material does not move when reversibly switched between the high and low reflective states. Also provided are methods of modulating an optical signal utilizing such electro-optic reflective modulators.

Abstract: The present invention pertains to an optical shutter comprising an photon-absorbing layer and a surface layer in a transparent state on at least one side of the photon-absorbing layer, wherein the optical shutter is characterized by the absorption of photons to change the photon-absorbing layer to an opaque state and to change the surface layer to a reflective state. The optical shutter is reversibly imageable between these transparent and reflective states. The optical shutter may comprise a metallized layer on at least one side of the photon-absorbing layer. Preferably, the optical shutter comprises an organic free radical compound, such as a salt of an aminium radical cation, in the photon-absorbing layer. Also provided are optical switch devices and optical buffers comprising such optical shutters and methods of switching an optical signal utilizing such optical shutters and switch devices.

Abstract: The present invention pertains to an optical shutter comprising an organic free radical compound, wherein the optical shutter is reversibly imageable to switch between a non-reflective and transparent state and a reflective state. This switching may be induced by the absorption of photons, the application of an electric current, or thermally. Preferably, the organic free radical compound is a salt of an aminium radical cation. Also provided are optical switch devices and optical buffers comprising such optical shutters, methods of switching an optical signal utilizing such optical shutters and switch devices, and methods of storing an optical signal utilizing such optical buffers.

Abstract: The present invention pertains to an optical shutter comprising an organic free compound, preferably a radical cation or a radical anion, wherein the organic free radical compound forms an oxidized or a reduced product having a change in absorption in a near-infrared or a visible wavelength region as a result of a photo-induced electron transfer reaction of the free radical compound. Preferably, the photo-induced electron transfer reaction occurs in less than 0.1 nanoseconds after absorption of photons by the free radical compound. Also, preferably, the change in absorption is reversible and occurs in less than 10 milliseconds. Also provided is an optical shutter for use as an optical switch in fiber optic communications, and, alternatively, for use in a laser protection device, a security protection system, and an eyewear device.

Abstract: The present invention pertains to an optical shutter comprising a photon-absorbing layer and a surface layer in a transparent state on at least one side of the photon-absorbing layer, wherein the optical shutter is characterized by the absorption of photons to change the photon-absorbing layer to an opaque state and to change the surface layer to a reflective state. The optical shutter is reversibly imageable between these transparent and reflective states. The optical shutter may comprise a metallized layer on at least one side of the photon-absorbing layer. Preferably, the optical shutter comprises an organic free radical compound, such as a salt of an aminium radical cation, in the photon-absorbing layer. Also provided are optical switch devices and optical buffers comprising such optical shutters and methods of switching an optical signal utilizing such optical shutters and switch devices.

Abstract: An optical amplifier includes an organic luminescent free radical compound, preferably a salt of a radical cation or a salt of a radical anion, wherein an excited state of the luminescent free radical compound undergoes stimulated emission in an infrared wavelength region, such as 1500 to 1650 nm. Suitable organic luminescent free radical compounds include aminium infrared-absorbing dyes.

Abstract: The present invention pertains to an optical shutter comprising an organic free compound, such as a radical cation or a radical anion, and a polydiacetylene compound, wherein the polydiacetylene compound is characterized by having a change in absorption in a wavelength region as a result of a photo-induced heat transfer from the free radical compound. The thermochromic change in absorption is reversed by thermal cooling or by a photo-induced reaction after the photo-induced heat transfer. Also provided is an optical shutter for use as an optical switch in fiber optic communications, and, alternatively, for use in a laser protection device, in a security protection system, or in an eyewear device.