Robert Alfred Bartolini

High‐performance Te trilayer for optical recording

The optical‐recording characteristics of a fully encapsulated Te trilayer structure are reported. The results demonstrate a 400% improvement in sensitivity compared to a Ti trilayer, at a recording wavelength of 488 nm, while maintaining high SNR (≳50 dB) on playback. This Te trilayer can be optimized for use with a GaAs diode laser recording system.

Optical grating coupling between low‐index fibers and high‐index film waveguides

Grating couplers between low‐refractive‐index (n ≈1.5) optical fibers and high‐refractive‐index (n ≈2.2) electro‐optic planar guides have been analyzed and demonstrated. Coupling efficiencies of 6% between single modes of a film and a fiber have been observed. Efficiencies of approximately 86% between single‐mode fibers and films using blazed backward‐wave gratings are predicted. In addition, low‐loss low‐optical‐aperture multimode fibers may be coupled to single‐mode films with efficiencies greater than 50% and angular spreads less than 0.5°.

Organic recording medium for volume‐phase holography

A new organic recording medium for volume‐phase holography is described. Holograms can be read out nondestructively at the recording wavelength and power. Self‐erasure may also be obtained. Holographic data and the effect of structure on recording and fixing behavior are described. The recording medium may be used to record multiple holograms.

Diode laser optical recording using trilayer structures

A new high-power diode laser and a more sensitive trilayer disk structure useful for FM video and digital data recording have been demonstrated. The diode laser is a constricted double-heterojunction large optical cavity (CDH-LOC) device capable of up to 100 mW output power in a single stable mode. By improving the thermal efficiency of the trilayer structure, the sensitivity is improved by a factor of two over previously reported trilayer structures. Digital signals with data rates up to 30 Mbits/s and storage capacity in excess of 3 \times 10^{10} bits are demonstrated using a plastic 12 in diameter disk rotating at 30 r/s while digital systems with data rates up to 60 Mbits/s and storage capacity in excess of 1011bits are shown to be feasible.

Multiple storage of holograms in an organic medium

The multiple storage of volume phase holograms in samples of camphorquinone in an acrylic polyester is discussed.

Nonpolymeric organic host for recording volume phase holograms

Sucrose benzoate has been used as a host for recording volume phase holograms. Diffraction efficiencies up to 75% are obtained using a variety of photosensitive guests. Fixed or self‐erasing holgrams can be obtained.

Organic Materials For Optical Devices

Organic materials have been used for volume phase holographic recording media and for integrated optical devices. A summary of the chemical and physical properties of the organic materials which we have investigated is presented. We discuss the relationship of the optical properties of the materials to the device parameters and show how concurrent physical measurements including interferometry, EPR, and absorption and emission spectroscopy, have led to a consistent model for the mechanism of hologram formation, which involves the production of free radicals by hydrogen abstraction.