Improved sensitivity in blue-membrane bacteriorhodopsin films.

We show that D85N/V49A, a mutant bacteriorhodopsin in which two residues, aspartate (D) at position 85 and valine (V) at position 49, have been replaced with asparagine (N) and alanine (A), respectively, has significantly improved optical properties compared with other forms of blue-membrane Bacteriorhodopsin. Absorption studies of the mutant in gels show that it forms the P(490) state at light levels that are comparable with M-state formation in wild-type films. Theoretical calculations based on Kramers-Kronig transformation of light-induced absorption data predict that the refractive index is three times larger than that of mutant D85N.

Multilayer volume holographic optical memory.

We demonstrate a scheme for volume holographic storage based on the features of shift selectivity of a speckle reference-wave hologram. The proposed recording method permits more-efficient use of the recording medium and yields greater storage density than spherical or plane-wave reference beams. Experimental results of multiple hologram storage and replay in a photorefractive crystal of iron-doped lithium niobate are presented.

Analysis of a micropolarizer array-based simultaneous phase-shifting interferometer.

Recent technological innovations have enabled the development of a new class of dynamic (vibration-insensitive) interferometer based on a CCD pixel-level phase-shifting approach. We present theoretical and experimental results for an interferometer based on this pixelated phase-shifting technique. Analyses of component errors and instrument functionality are presented.

Holographic profilometry with a rhodium-doped barium titanate crystal and a diode laser.

We present a novel, whole-field, noncontact profilometer based on real-time, two-color contour holography. A single 30-mW laser diode was used to record a hologram in a BaTiO(3):Rh crystal, and the reconstructed image was interfered with the real-time object wave. Current modulation of the diode laser produced continuously tunable contour intervals.

Resonant holographic interferometry with ZnTe:V:Mn.

The photorefractive semiconductor ZnTe:V:Mn is investigated for use in real-time resonant holographic interferometry applications. Experimental results of two-wave and four-wave mixing with pulsed dye and cw diode lasers are presented; in addition holographic image transfer, as well as two-wavelength resonant holographic interferometry, are demonstrated. Species-specific interferograms of potassium seeded into various combustion environments are captured at video-frame rates.

Real-time resonant holography using bacteriorhodopsin thin films.

We demonstrate real-time, two-dimensional measurement of species concentration in a turbulent flow field. The dynamics of pulsed holographic recording and decay are characterized for a 46-microm polymer film containing bacteriorhodopsin. We produced species-specific holographic interferograms of sodium vapor by simultaneously recording two holograms at different wavelengths, one tuned near a sodium absorption feature and the other tuned off resonance.

Room-temperature 1.06-0.53-microm second-harmonic generation with MgO:LiNbO(3).

Room-temperature 1.06-0.53-microm second-harmonic generation (SHG) achieved with LiNbO(3) doped with 7 mol.