We focus on the fabrication and study of controllable holographic gratings based on azo-dye-doped and undoped polymer-ball-type polymer-dispersed liquid-crystal films. Experimental results indicate that the next step of photopolymerization of the sample with the illumination of Ar+ laser beams after UV curing causes a latent density grating to be recorded. This grating is formed by a selective ...

Based on the modified Kogelnik diffraction efficiency equation, we study the diffraction intensity spectrum and the total diffraction efficiency of reflection volume holographic gratings in photorefractive media. Taking photorefractive LiNbO3 crystal as an example, the effect of the grating parameters and the pulse width on the diffraction properties is presented under the influence of crystal ...

We present results from cryogenic tests of a Volume-Phase Holographic (VPH) grating at 200 K measured at near-infrared wavelengths. The aims of these tests were to see whether the diffraction efficiency and angular dispersion of a VPH grating are significantly different at a low temperature from those at a room temperature, and to see how many cooling and heating cycles the grating can withstan...

We replace the traditional grating used in a dispersive spectrometer with a multiplex holographic grating to increase the spectral range sensed by the instrument. The multiplexed grating allows us to measure three different, overlapping spectral bands on a color digital focal plane. The detector's broadband color filters, along with a computational inversion algorithm, let us disambiguate measu...

We report the fabrication and the optical characterization of a hybrid tunable integrated optical filter. It consists of a diffused ion-exchanged channel waveguide on a borosilicate glass substrate with a cover of the same glass to form a gap filled with a holographic grating. The grating morphology, called POLICRYPS (POlymer LIquid CRYstal Polymer Slices), is made of alternating stripes of pol...

Electrically switched distributed-feedback (DFB) lasing action is presented in a Pyrromethene 580 lasing dye-doped holographic polymer dispersed liquid crystal (H-PDLC) transmission grating structure. This design, when compared with the previously utilized H-PDLC reflection grating structure, has the advantage of a greatly enlarged gain length (10 mm) and a low concentration of liquid crystal (...

We have studied the optical properties of electrically switched holographic gratings fabricated using polymer-dispersed liquid crystal (PDLC) materials. We have found that the PDLC mixture can be used to control the diffractive properties of the composite gratings, including the anisotropy of the grating. 2000 Optical Society of America OCIS codes: (050.0050) Diffraction and gratings, (050.733...