| 摘要 |
An electromagnetic imager device can detect electromagnetic images, for example, in the infrared, millimeter and microwave wavelengths and convert these images into useful wavelengths which imaging devices, such as a camera, can record. The electromagnetic imager includes an interferometer having one arm thereof filled with a gaseous mixture. The particular gaseous mixture used, improves the accuracy of the device by enhancing the probability of an exchange of kinetic energy for molecular internal energy during molecular collision. The electromagnetic image is absorbed in an internal mode of the molecular species in the gas over an absorption depth. The absorption of the electromagnetic energy causes heating in the gas which, in turn, causes local changes in the index of refraction in the focal plane of the gas. These changes in the index of refraction phase modulate the phase front of the laser beam passing through the gas. The local index of refraction variations thus result in a direct mapping of the absorbed electromagnetic energy image allowing the image to be detected by interferometric means. |
