Spectroscopy, persistent hole burning, and holographic applications of naphtophthalocyanine/haloanthracene systems

Abstract

We report on the spectroscopic and hole burning properties of free-base naphtophthalocyanine with and without 1-chloranthracene in polymer host. These materials exhibit a strong 0-0 absorption band in the region 800 nm matching the wavelength range of most semiconductor and Ti:Sapphire lasers. The materials studied feature two persistent hole burning photochemical mechanisms, i.e. one-photon proton tautomerization, and two-photon-gated hole burning likely due to donor-acceptor electron transfer. The last mechanism includes the long living intermediate state. The hole width at 1.5 K is about 300-400 MHz depending on the hole burning conditions, while the inhomogeneous width is about 10 7 MHz. Holographic storage is an important potential application of these materials. We demonstrated 10 plane wave holograms angularly multiplexed at one frequency channel in a spectral hole burning medium. It was shown that the M=# is still a valid system metric and the measured M=# in one frequency channel is about 0.01. r

Power budget analysis of image-plane storage in spectral hole-burning materials

“…At cryogenic temperatures for example, Eu-YSO provides a per-spot capacity bound of CoB=Dn H ¼ 10 GHz/10 kHz=10 6 bits. It is this potentially large storage density that has motivated many previous studies of HBM-based optical memory including frequency-domain, time-domain, and hybrid approaches [9][10][11][12][13]. In contrast to previous analytical approaches [14][15][16][17], we start with fixed system requirements and known material parameters and then allow all other parameters (including spot size, written hole depth, and optical thickness) to vary in order to optimize the system design for minimum total (write and read) power requirements to achieve a high performance (non-archival) memory module.…”

Long-delay engraving and recovery of chirped femtosecond pulses by spectro-temporal holography in spectral hole-burning molecular solids

“…In typical materials for hole burning storage in the 800 nm range, i.e., naphthalocyanines-doped polyvinylbutyral, the inhomogeneous bandwidth is of the order of 3000 GHz, allowing to store optical pulses as short as 50 fs. The homogeneous hole width in these materials is of the order of 0.1 GHz at temperatures below 4 K [6,7], allowing to store pulses longer than 1 ns. Such material should make possible the registration of the spectral interference between femtosecond pulses separated by nanosecond time delays.…”