Polarization-interferometric nonlinear confocal microscopy is proposed for measuring a nano-sized object (such as nano
particle) with lower linear absortion. A three-dimensional distribution of third-order nonlinear dielectric polarization was
We propose a new optical data storage system with minute spheres. To avoid a problem of jitter as instability of rotating disk speed and fluctuation of recording bit formation, we have devised a new process. The process involves the use of dye-doped minute spheres arranged upon a surface-relief structure as recording bits. Alternate laminating recordable sphere layer with sensitivity and buffer layer with insensitivity structurally limits recording bits in three dimensions. We can limit a sensitive region within a sphere diameter. A reflection-type confocal optical microscope can read out both bit signals and shape signals from minute spheres at high resolution. Confocal relection of ~10% was measured before and after recording from a single minute sphere with Spiropyran as a recording dye. Also, the shape signal from each minute sphere is utilized as a clock signal in recording and readout. The clock signal can be produced by separating a high-level signal and a low-level signal on the basis of a threshold. In our minute-sphere optical storage system, a shift between positions of the recording bit and the clock signal does not occur because the clock signal is generated based on the shape signal from a minute sphere as the recording bit. This jitter-free technique proved to be extremely effective for disk recording and readout.
We have fabricated a new optical storage media using minute spheres arranged on surface relief grating (SRG). By using minute spheres as recording bits, we can limit recordable regions by sphere size, since one mintue sphere becomes one recording bit. We can realize high resolutive reconstruction in the plane direction. We make surface relief structures on a polymer thin fim, and tried to perform diffusion arrangement and adsorptive fixation of minute spheres on it. The stability of arranged spheres was confirmed for heating and washing. Furthermore, we tried dipping method for more simple arranging minute spheres on a large area of the substrate and have made a monolayer sample of the spheres. We are able to realize high sensitive reconstruction of the media using the confocal optical system as record and readout systems. We have also succeeded in doping the recordable dyes in minute spheres.
Simple fabrication technique of nonlinear optical waveguide components in polymer films based on simultaneous embossing and poling at elevated temperature (SEPET) is proposed and demonstrated. The master gratings which consist of polyimide die and metal base are fabricated by a single pulse two-beam interference technique using UV laser ablation. The master grating is found to be stable enough against heat and mold treatment cycles. The master molds nonlinear optical polymers at their Tg's. At the same time, high voltage is applied to the polymers to induce second-order nonlinearity. The grating profile as well as the nonlinearity is estimated. Moreover, formation of channel waveguide with grating based on the present process is also discussed.
The properties of phase conjugate (PC) beams generated by an erythrosin/polyvinyl alcohol film are briefly reviewed along with demonstrations of PC interferometries, and an experimental study of the time dependence of the phase difference between saturable absorption and holographic components of the PC signal is reported. The results show that the phase difference between two components of PC signals changed temporally with a period of about nine minutes and reached 110 deg five minutes after the initiation of degenerate four-wave mixing at the pump beam intensity of 1 W/sq cm.
Polymer lightguides ofPMMA, doped with azo dyes are investigated with respect to their
opto-optical or all optical properties. The TRANS-CIS photoisomerisation of the azo dyes
leads to reasonable polarization dependent optically induced refractive index changes.
These are studied in planar lightguides and in leaky guides.
With light at the absorption edge all optical properties are studied leading to a possible
application as bistable device.