Optical transistor

Zeolites provide a novel host for the generation of semiconductor hyperlattices within their pore volume. The control of the connectivity between the clusters of semiconductor is unparalleled in any other host medium and so has allowed a detailed study of the optical consequences of such connectivity6. However, from the practical standpoint, such materials have some severe drawbacks - most notably the lack of single crystals of sufficient size to produce viable optical devices such as optical transistors or spatial light modulators. We have therefore moved on to look at more practical/processable quantum-dot materials such as semiconductor-doped porous glasses. 

See also Battery Calculator Fiber optics Transistor. 

X< ) ( —(o CO, CO, — co) Self-focusing, degenerate four-wave mixing, optical Ken-effect Optical bistability, phase conjugation, optical transistors, image processing... 

The future of this line of research lies not in the enzyme mimicry described above but more in the novel optical and especially non-linear optical properties of quantum confined semiconductor systems - the production of optical computer elements such as optical transistors, spatial light modulators and phase conjugate materials. From the biomimetic perspective we are moving in the direction of the silicon-based brain ... 

Fig. 3.12 The transmittance behavior of a transphasor (optical transistor). Plot of the transmitted intensity as a function of the incident intensity.

The intramolecular electron transfer in the closed-ring isomer of the dyad was attributed to a transfer from the perylenebisimide chromo-phore to the dithienylethene unit. The dyad (100) is useful for ultra-high-density optimal memories and super-high-resolution fluorescence imaging. The triad (101) showed the key functionalities of an optical transistor. Gating and amplification could be operated with photons instead of electrons. 

Wang, Z., Hagan, D. J., Van Stryland, E. W., and Assanto, G., Phase-insensitive, single wavelength, all-optical transistor based on second order nonlinearities. Electron. Lett., 32, 1135-1136 (1996). 

Polydiacetylenes are polymers showing a one-dimensional semiconducting behaviour. This one-dimensional structure causes exceptionally high third order non-linearities [100], also in off-resonant wavelength regions [101], with extremely short sub-picosecond switching times [102]. After this discovery it was believed that an optical amplifying switch (optical transistor) or even an optical computer was close at hand. 

Silicon is also alloyed with germanium (Si Gei.x) for applications such as heterojunction bipolar transistors and optical emitters... 

Optoelectronic components produced by CVD include semiconductor lasers, light-emitting diodes (LED), photodetectors, photovoltaic cells, imaging tubes, laser diodes, optical waveguides, Impact diodes, Gunn diodes, mixer diodes, varactors, photocathodes, and HEMT (high electron mobility transistor). Major applications are listed in Table 15.1.El... 

Although astronomy is accustomed to the detection of a few photons per pixel, the electric charge of a few electrons is extremely small. A critical part of the design of a focal plane array is the amplifier which converts the small amount of charge in each pixel into a signal that can be transmitted off the detector. The amplifier in an optical or infrared detectors is typically a field effect transistor (FET), a solid state structure which allows a very small amount... 

These high-profile developments were accompanied by improvements in technology such as electronics, particularly the advent of transistors and integrated circuit boards, fiber optics, and computer interfaces. 

There are three major classes of palladium-based hydrogen sensors [4], The most popular class of palladium-based sensors is based on palladium resistors. A thin film of palladium deposited between two metal contacts shows a change in conductivity on exposure to hydrogen due to the phase transition in palladium. The palladium field-effect transistors (FETs) or capacitors constitute the second class, wherein the sensor architecture is in a transistor mode or capacitor configuration. The third class of palladium sensors includes optical sensors consisting of a layer of palladium coated on an optically active material that transforms the hydrogen concentration to an optical signal. 

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