MIM diodes

Fowler-Nordheim Tunneling in Semiconducting Polymer MIM Diodes... 

Improvements in these different techniques may come from either improved diodes or detection schemes. The nonlinearities measured in the current-VOItage curves of our MIM diodes are extremely small and conversion efficiencies could be 100 times larger. We are optimistic that better materials which will result in larger FIR powers may be found. Differential detection schemes would also significantly improve the sensitivity and permit the detection of weaker lines. The sensitivity, however, is still only about 1% of that of laser magnetic resonance. Laser magnetic resonance is useful only for paramagnetic... 

An efficient way to generate coherent, tunable radiation in the far infrared is the difference frequency generation by mixing the output of an CO2 laser kept on a selected line with the output of a tunable CO2 waveguide laser in a MIM diode (Vol. 1, Sect. 5.8). With this technique Stark spectra of CHsOH were measured over a broad spectral range [149]. 

For measurements of optical frequencies, ultrafast metal-insulator-metal (MIM) diodes have been developed [4.110], which can be operated up to 66THz (k = 3.39 xm). In these diodes, a 25-fim diameter tungsten wire, elec-trochemically etched to a point less than 200 nm in radius, serves as the point contact element, while the optically polished end of a nickel plate with a thin oxide layer forms the base element of the diode (Fig. 4.89). 

These MIM diodes can be used as mixing elements at optical frequencies. When illuminating the contact point with a focused CO2 laser, a response time of 10 s or better has been demonstrated by the measurement of the 88-THz emission from the third harmonic of the CO2 laser. If the beams of two lasers with the frequencies f and /2 are focused onto the junction between the nickel oxide layer and the sharp tip of a tungsten wire, the MIM diode acts as a rectifier and the wire as an antenna, and a signal with the difference frequency f — f2 is generated. Difference frequencies up into the terahertz range can be monitored [4.111] (see Sect. 5.8.7). The basic processes in these MIM diodes represent very interesting phenomena of solid-state physics. They could be clarified only recently [4.111]. 

Fig. 4.89. Arrangement of a metal-insulator-metal (MIM) diode used for optical frequency mixing of laser frequencies...

A very useful frequency-mixing device is the MIM diode (Sect. 4.5.2), which allows the realization of continuously tunable FIR radiation covering the difference-frequency range from the microwave region (GHz) to the... 

Fig. 5.118. Generation of tunable FIR radiation by frequency mixing of two CO2 laser beams with a microwave in a MIM diode...

These MIM diodes can be used as mixing elements at optical frequencies. When illuminating the contact point with a focused CO2 laser, a response time of 10 " s or better has been demonstrated by the measurement of the 88-THz emission from the third harmonic of the CO2 laser. If the beams of two lasers with the frequencies... 

An example image displayed on the MIM diode addressed matrix liquid crystal display panel is shown in Fig. 6 [27], The actual display area is 100x96 mm. There are 240 gate and 250 data electrodes which provide a resolution of 25 lines cm . The contrast ratio obtainable is very high. 

For measurements of optical frequencies, ultrafast Metal-Insulator-Metal (MIM) diodes have been developed [4.107], which can be operated up... 

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