Recording three-dimensional optical

Spiropyrans show promise for optical recording, three-dimensional optical memories,214 and holography.215 The dyes currently under study for these applications very probably will not be used merely dissolved in a bulk polymer matrix, but will be oriented in films and membranes, or adsorbed or vapor deposited on solid substrates to take advantage of the nonlinear optical properties of the colored forms. For example, thick (0.5 mm) PMMA films of 6-nitro-thiaBIPS can be used to record wavelength-multiplexed volume holograms with an infrared diode laser. This system is impractical at present because of fatigue and poor diffraction efficiencies.216... 

Mizuno, T. Yamasaki, K. Misawa, H. Three-dimensional optical memory in a photoacid-induced recording medium. Jpn. J. Appl. Phys., Part 1 2005, 44, 6593-6595. 

Another experimental proof of the localization of cold atoms at the minima of a periodic optical potential was obtained by recording the resonance fluorescence spectra of cesium atoms trapped in three-dimensional optical molasses (Westbrook et al. 1990) and rubidium atoms in a one-dimensional optical potential (Jessen et al. 1992) The resonance fluorescence spectrum of a motionless two-level atom consists of the well-known Mollow triplet, which includes a central peak at the laser frequency u> and two side components displaced to the red and blue sides by an amount equal to the Rabi frequency (Mollow 1969). For a two-level atom oscillating in a potential well at a frequency lower than the Rabi frequency, each component of the Mollow triplet is split into side components corresponding to changes in the vibrational state of the atom. If the ratio between the oscillation amplitude of the atom in the potential well and the radiation wavelength (the Lamb-Dicke factor) is small, each component of the... 

One of the features of confocal microscopy is that it can produce optical slices of defined thickness through thick specimens. Using a lens of high numerical aperture, thickness of the confocal sections can reach a theoretical limit of about 0.5 pm. Therefore, by moving the specimen up and down, a three-dimensional (3-D) image can be recorded. 

The application of holography to plasma interferometry has several advantages 276) accurate alignment and precision optical elements are not required. A complete three-dimensional record of the interference phenomena is obtained and the technique is well suited to record stationary and transient plasmas. Two-wavelength holographic interferometry of partially ionized plasmas has been performed by Jeffries 277). 

Point spread function (PSF) If a tiny population of 100 nm fluorescent beads sandwiched between a coverslip and a microscope slide are examined at high resolution (i.e. at 100x objective magnification, 1.4 NA. and in a correctly matched refractive index of oil), it can actually show a tiny set of rings in the horizontal (XY) view (also called an airy disk (see Fig. below). This airy disk cannot be avoided due to diffraction and the wave nature of light. If a specimen is optically sectioned and projected in a vertical (XZ) view (see Fig. xx), a set of concentric rings will flare from the center. When a three-dimensional image of this specimen is collected, a complete point spread function is said to be recorded for each bead. The (PSF)... 

There are two ways to achieve higher density the extension of the data-recording space in the axial direction, and the reduction of bit size. In this chapter, we describe a method for overcoming the density limit, namely, introduce an additional axial dimension in the recording process. " " The z or longitudinal axis is used in addition to the surface dimension (x—y space) of conventional optical memory. The data are thus written not on the material surface but within the three-dimensional (3D) thick volume. The media that can be used are photochromic materials. ... 

Figure 16.1 shows a principle of bit-oriented three-dimensional (3D) optical memory. A laser beam is focused on a point in a recording medium. Chemical reactions of the medium should be induced at that spot because extremely high intensity is produced at the focus point. By 3D scanning of the focus... 

Fukaminato, T., Kobatake, S., Kawai, T, and Irie, M. Three-dimensional erasable optical memory using a photochromic diarylethene single cry stal as the recording medium. Proc. Jpn. Acad. 77, B, 30, 2001. 

Holography - A technique for creating a three-dimensional image of a object by recording the interference pattern between a light beam diffracted from the object and a reference beam. The image can be reconstructed from this pattern by a suitable optical system. 

A photorefractive polymer consisting of DMNPAA, TNF, ECZ, and PVK has been used for erasable/rewritable three dimensional bit optical data storage under two-photon excitation. A three dimensional bit density of 5 Gbits/cm(3) is achieved by pulsed beam illumination at an infrared wavelength of 800 nm in the recording process. 

Many lay cell biologists use confocal imaging to refer to anything from a simple digital recording of a single focal plane to a full three-dimensional data By fluorescence LM, 1 mean use of a compound light (optical) microscope equipped for epifluo-... 

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