Optofluidic pressure sensor based on interferometric imaging

We present a chip-scale optofluidic interferometric sensor for measuring liquid pressure based on an imaging method. The chip was constructed with a polymer by multilayer soft lithography. It consists of a flexible air gap optical cavity, which, upon illumination by monochromatic light, generates interference patterns that depend on pressure. The pressure was measured by imaging and analyzing the interference patterns. We also employed a pattern recognition algorithm that significantly simplified the calculation and enhanced the measurement reliability. This pressure sensor was demonstrated with a working range of 0-22 psi and an accuracy of ±1.4% of full scale when temperature stabilized.     

Holographic grating formation in a colloidal suspension of silver nanoparticles

Holographic gratings are recorded in colloidal suspensions of silver nanoparticles by utilizing interfering nanosecond pulses. The diffraction efficiency is measured with continuous-wave light. An instantaneous response together with a transient grating are observed: the nanoparticles absorb the pump light and heat up. Heat is transferred to the solvent, and a delayed thermal grating appears. The final decay time constant of this grating depends quadratically on the period length and has a typical value of 1 micros for grating spacings of several micrometers.     

Holographic recording of laser-induced plasma

We report on a holographic probing technique that allows for measurement of free-electron distribution with fine spatial detail. Plasma is generated by focusing a femtosecond pulse in air. We also demonstrate the capability of the holographic technique of capturing the time evolution of the plasma-generation process.     

Sensitivity improvement in two-center holographic recording

Persistent holograms are recorded with green light in LiNbO(3) crystals doped with Mn and Fe. The recording sensitivity is 20 times better than that obtained by recording with red light. Partial loss of persistence is caused by using green light for recording.     

Real-time spectral imaging in three spatial dimensions

We report what is to our knowledge the first volume-holographic optical imaging instrument with the capability to return three-dimensional spatial as well as spectral information about semitranslucent microscopic objects in a single measurement. The four-dimensional volume-holographic microscope is characterized theoretically and experimentally by use of fluorescent microspheres as objects.     

Characterization of phenanthrenequinone-doped poly(methyl methacrylate) for holographic memory

The holographic recording characteristics of phenanthrenequinone- (PQ-) doped poly(methyl methacrylate) are investigated. The exposure sensitivity is characterized for single-hologram recording, and the M/# is measured for samples as thick as 3 mm. Optically induced birefringence is observed in this material.     

Information capacity of 3-D holographic data storage

Capacities for angular and wavelength multiplexed holographic data storage systems are considered. Limitations due to the spatial resolution of the recording and reconstructing fields and to the holographic recording process are derived.     

Tritiation of two potent catecholamine beta-adrenergic receptor agonists

The tritiation of the beta-adrenergic catecholamines isoproterenol and hydroxybenzylisoproterenol is described.