We report on the development of a novel multiplexing Raman spectroscopy technique using a single laser light together with a volume phase holographic (VPH) grating that simultaneously acquires both fingerprint (FP) and high wavenumber (HW) tissue Raman spectra at endoscopy. We utilize a customized VPH dual-transmission grating, which disperses the incident Raman scattered light vertically onto ...

Photorefractive polymers have been extensively studied for over two decades and have found applications in holographic displays and optical image processing. The complexity of these materials arises from multiple charge contributions, for example, leading to the formation of competing photorefractive gratings. It has been recently shown that in a photorefractive polymer at relatively moderate a...

Recent advances in large format detector arrays and holographic diffraction gratings have made possible the development of imaging spectrographs with high sensitivity and resolution, at relatively low component cost (<$100K.) Several airborne instruments have been built for the visible and near infrared spectral band with 10-nm resolution, and SNR of 200:1. Three instruments are compared, an al...

We present a multicolor fluorescence imaging modality to visualize in real-time tissue structures emitting multispectral fluorescent light from different focal depths. Each designated spectrum of fluorescent emission from a specific depth within a volumetric tissue is probed by a depth-spectrum selective holographic grating. The grating for each fluorescent color are multiplexed within a volume...

In this work, we report the fabrication and optical characterization of a one-dimensional reflection holographic volume phase grating recorded in recently developed photomobile composite polymer mixture. The on material was periodic arrangement hard polymeric walls viscous regions. notch located near-infrared region electromagnetic spectrum. transmission efficiency modulated by an external CW l...

The regularities of energy transfer between two linearly polarized light waves as their contra-directional mixing on a volume reflection holographic grating formed in photorefractive Bi12GeO20 crystal the (001)-cut are analyzed. values thickness and azimuths linear polarization waves, at which amplification object wave is achieved, determined. change direction to opposite, depending crystal, ha...

Flatness of the wavefront diffracted by grating can be mandatory for some applications. At ambient temperature, the wavefront diffracted by a volume phase holographic grating (VPHG) is well mastered by the manufacturing process and can be corrected or shaped by postpolishing. However, to be used in cooled infrared spectrometers, VPHGs have to stand and work properly at low temperatures. We pres...