Abstract: A thermal infrared (TIR) signaling device includes and exothermally reactive material such as charcoal, which when ignited, burns and emits an infrared (IR) signal in a TIR wavelength band. The IR signal is modulated to reach a defined field of view in a required blinking pattern. The blinking may be intermittent. Exemplarily, the modulation achieved by a rotating mirror with reflective front- and back-sides, the back-side used to reflect the sky. Optionally, the device may include a detector sensitive to range-finder radiation and operationally connected to an ignition train which includes an igniter for igniting the reactive material and/or a built-in test unit for providing the user with an indication of a device status.

Abstract: Optical devices, are provided, having a first conductive layer, an optical layer, arranged over the first conductive layer, and a second conductive layer, arranged over a portion of the optical layer, in accordance with a predetermined pattern. The optical layer is transparent to at least a wavelength of interest and has an index of refraction, which is a function of a variable, substantially reversible, dopant concentration or dopant concentration gradient in it. By applying an electric potential between the first and second conductive layers, a change in the index of refraction is formed within the optical layer, between the portion abut with the predetermined pattern and the remainder of the optical layer.

Abstract: Optical devices, are provided, having a first conductive layer, an optical layer, arranged over the first conductive layer, and a second conductive layer, arranged over a portion of the optical layer, in accordance with a predetermined pattern. The optical layer is transparent to at least a wavelength of interest and has an index of refraction, which is a function of a variable, substantially reversible, dopant concentration or dopant concentration gradient in it. By applying an electric potential between the first and second conductive layers, a change in the index of refraction is formed within the optical layer, between the portion abut with the predetermined pattern and the remainder of the optical layer.

Abstract: A system for remote near infra red (NIR) spectral analysis of hydrocarbons using telecommunication optical fibers for real-time on-line transmission of NIR spectral information from an examined hydrocarbon sample to a remote analyzer comprising (a) a light source for generating near infra red radiation; (b) an optical probe head being at on-line contact with an analyzed hydrocarbon sample; (c) at least one telecommunication transmitting optical fiber for inputting the near infra red radiation into the optical probe head, such that the radiation passes at least once through the hydrocarbon sample, such that a spectrum of the sample is generated; (d) a detector for analyzing the spectrum, the detector and the light source being part of an analyzer; and (e) at least one telecommunication receiving optical fiber for receiving the radiation after the passing through the sample and inputting the radiation into the detector.