Optical variable device

OVD optical variable device PASU polyary Isulfone... 

A process to make and metallize a hologram will be described. Other optically variable devices or microimages will not be mentioned further in order to simplify the discussion. However, these images can be metallized similarly. 

Optically variable device (OVD) A device that presents a different appearance when viewed from different angles. Often used as a security measure. 

Note that a quadrupole mass speciromeicr is more analogous to an optical variable-band filter photometer than to an optical spectrometer in which a grating si-mullaneously disperses a spectrum of clcctromagnclic radiation. For this reason, the device is sontetimes referred to as a mass filter rather than a mass analyzer. 

Ru -Ru species that display intense intervalence charge-transfer bands at 1550 nm, close to the telecommunication wavelength of 1.5 pm (Fig. 8.6). Cross-linked films can be used in variable optical attenuator devices, and stability over 18,000 switching cycles was demonstrated with a response time of ca. 2 s (see Fig. 8.7) [99, 100]. 

Fig. 8.7 Variation of current (top) and transmittance (bottom) as a function of time for a variable optical attenuator device that uses crosslinked films of dendrimer 8.44 for 5 s A/itches (step time 2 s). (Adapted from [100])...

A special case are ion storage layers with complementary electrochromic activity, which may be assembled with a PEDOT layer. In a complementary electrochromic cell, both layers—dye and bleach—simultaneously increase to the overall optical contrast. Tungsten trioxide as well as Prussian Blue, iron(III) hexacyanoferrate(II/III) bleach upon reduction and were used in combination with PEDOT. Cells made from PEDOT in combination with Prussian Blue exhibited a deep blue-violet color at a potential of -2.1 V and become light blue at 0.6 V. Combination cells of alkylenedioxypyrrols or -thiophenes with ferrocene have been proposed as variable optical attenuator devices due to a large dynamic range of optical attenuation at the telecommunication wavelength of 1550 nm. ... 

Department of Energy (US) Design of experiments Digital object identifier (intellectual property) Dioctyl phthalate Department of Transportation Diffractive optically variable image device Diffusion pump... 

In an electrooptic material the phase retardation angle is controlled by altering birefringence, which is in turn controlled by the potential of an apphed electric field. An electrooptic device thus acts as a variable phase optical retardation plate, and can be used to modulate the wavelength or intensity of an incident beam. 

In order to compensate for the distortions in the wavefront due to the atmosphere we must introduce a phase correction device into the optical beam. These phase correction devices operate by producing an optical path difference in the beam by varying either the refractive index of the phase corrector (refractive devices) or by introducing a variable geometrical path difference (reflective devices, i.e. deformable mirrors). Almost all AO systems use deformable mirrors, although there has been considerable research about liquid crystal devices in which the refractive index is electrically controlled. 

We measured and analyzed the vertical emission from the resonators under pulsed optical pumping. The experimental setup is illustrated in Fig. 12.8a A Ti/sapphire mode-locked laser was used to optically pump the devices at a center wavelength of 980 nm, repetition rate of 76.6 MHz, and pulse duration of approximately 150 fs. A variable attenuator was used to control the pump power. The average pump power and center wavelength were monitored by a wavemeter, through a 50/50 beamsplitter. The pump beam is focused on the back side of the sample with a 50 x objective lens. A 20 x objective lens is used to collect the vertical emission from the sample and to focus it on an IR camera to obtain the NF intensity pattern and to... 

Fig. 16.5 Response to refractive index interrogation of a single NOSA waveguide, (a) Output spectrum for a NOSA where one of the five resonators is fluidically targeted, first with water and then with a CaCl2 solution. The resonance of the targeted resonator shifts toward the red end of the spectrum due to the higher refractive index of the CaCl2 solution, (b) Experimental data (with error bars indicating inter device variability) showing the redshifts for various refractive index solutions. The solid line is the theoretically predicted redshift from FDTD simulations. The experimental data is in excellent agreement with the theory. Reprinted from Ref. 37 with permission. 2008 Optical Society of America...

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