Pictures taken with most camera flashlights are often considered unnatural looking due to a mismatch of the illuminance and color temperature between the flash light and the ambient light in the scene. Subsequently, image rendering software is used to enhance the picture to a desirable look or several pictures must be taken attempting a better capture. A smart light system has been developed, incorporating LED sources and a sensor, that studies the lighting environment and decides optimal light for specific applications.
This invention is directed to a unique imaging microscope operating within the electromagnetic terahertz frequency regime for medical applications. Unlike optical spectroscopes that only measure the intensity of light at specific frequencies, the terahertz domain allows for the precise measurements of the refractive index and absorption coefficient of samples that interact with the terahertz waves. Various liquids and gases molecules interact within the terahertz frequency band and their unique resonance lines allow their molecular structure to be identified.
Freely propagating terahertz pulses are usually measured by sampling techniques such as photoconductive antenna or electro-optical sampling. Although these sampling techniques provide good signal-to-noise ratios and adequate temporal resolution, they cannot be used for measurement on a single-shot basis. The present invention provides a system for measuring a terahertz frequency pulse propagating in a free-space optical path using an optical streak camera and an electro-optical modulator.
Terahertz wave imaging has been used in various applications, such as security sensing and quality control inspection, for example. Terahertz wave two-dimensional (2D) imaging technology has been demonstrated as it dramatically reduces the time required for image acquisition. It can also support real-time terahertz wave imaging.
Terahertz (THz) radiation occupies a large portion of the electromagnetic spectrum between the infrared and microwave bands and is a developing frontier in imaging science and technology. In contrast to the relatively well-developed techniques for imaging at microwave and optical frequencies, however, there has been only limited basic research, new initiatives, and advanced technology developments in the THz band.
This invention is directed to a system and method to create three dimensional tomography using a Fresnel lens with broadband terahertz (THz) pulses.The procedure allows reconstruction of an objects tomographic contrast image by assembling the frequency-dependent images.Objects at various locations along the beam propagation path are uniquely imaged on the same imaging plane using a Fresnel lens with different frequencies of the imaging beam.
This invention is directed to techniques for obtaining and imaging three-dimensional objects using radiation in the terahertz (THz) spectrum and systems and associated methods for high resolution terahertz computed tomography. Although computed tomography is well known in X-ray radiographic imaging, a serious problem in reconstructing an image using THz computed tomography is that the THz wave does not satisfy the short wave limit as the X-ray satisfies in X-ray computed tomography.
Terahertz (THz) waves occupy a segment of the electromagnetic spectrum between the infrared and microwave bands. As such, they can be used for imaging and sensing in ways that are not possible with conventional technologies such as X-ray and microwave. Because THz radiation transmits through almost anything that is not metal or liquid, the waves can see through most materials that might be used to conceal explosives or other materials, such as packaging, corrugated cardboard, clothing, shoes, backpacks, and book bags. They are also safer than X-rays and microwaves for human tissue.
Electro-optic crystals and photoconductive dipole antennas have been widely used in terahertz (THz) time-domain spectroscopy and related imaging applications. In the standard apparatus used for THz time-domain spectroscopy a separate transmitter and receiver are used for the emission and detection of the THz signal. Because detection is the reverse process of emission, the transmitter and the receiver can be identical devices.
The cross-section of an X-ray phase shift image is a thousand times greater than that of X-ray attenuation in soft tissue over the diagnostic energy range implying phase imaging can achieve a much higher signal-to-noise ratio and substantially lower radiation dose than attenuation-based X-ray imaging. Grating interferometry is a state of the art X-ray imaging approach, which can simultaneously acquire information of X-ray phase-contrast, dark-field, and linear attenuation. This imaging modality can reveal subtle texture of tissues.