Solid state optical junction devices and arrays and systems incorporating same |
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| 申请号 | US38978373 | 申请日 | 1973-08-20 | 公开(公告)号 | US3898453A | 公开(公告)日 | 1975-08-05 |
| 申请人 | MASSACHUSETTS INST TECHNOLOGY; | 发明人 | JAVAN ALI; | ||||
| 摘要 | Optical radiation generation and detection using metal-to-metal diode junctions. Coherent optical radiation is generated by using an antenna connected to a metal-to-metal diode junction with nonlinear current-voltage characteristics and by coupling to the junction electromagnetic radiation energy to interact with the junction, causing emission from the antenna at optical frequency absent from the input. Optical diodes are shown in the forms of a mechanically contacted cat whisker system and as single and multiple microscopic solid portions in an integrated solid mass, defining both the antenna and the junction, preferably as a deposit of solid layers upon a substrate, preferably as overlapping printed circuit line structures. Arrays of such junctions provide enhanced effects; useful arrays include Franklin-Marconi geometries, fish-bone antennas and row and column arrays. Such solid diode constructions and arrays thereof are used not only for optical radiation generation but also detection and mixing including use in an image scanner, energy converter and a broad band detector. The diodes as a radiation source are used in combination with an absorbtion cell in spectroscopic analysis, a feedback loop in a stable frequency source, and an optical frequency communicating system. In a scanner, read-out from the junctions is shown indirectly, using an electron beam, and directly using leads connected to respective antennae. Local oscillators directing radiation upon an image disecting array, mixing in the junctions with incident radiation from the image create superheterodyne beats leading to improved levels of detection. By phase locking the local oscillator to the frequency of coherent image-illuminating radiation, and detecting phase of the beats relative to the illuminating radiation, as well as amplitude, a holographic display of the image is achieved. | ||||||
| 权利要求 | 1. An electronic device responsive to optical radiation incident thereupon to generate an electrical effect dependent upon the said incident radiation, said device comprising a solid nonmetallic substrate, a solid metal deposit thereon, a solid dielectric layer upon a portion of said metal deposit, and a second solid metal deposit on said substrate, said second metal deposit having a limited common area with said first metal deposit, the respective common portions of said metal deposits being in intimate contact with opposite sides of and separated by said dielectric layer, said dielectric layer being of limited thickness, said common region thereby defining a metal to metal junction, a portion of one of said metal deposits extending away from said junction having a width related to the wave length of said optical radiation and forming an antenna responsive to said incident radiation to generate an alternating electrical current at the frequency of said radiation and to conduct said current to said junction, said junction having a non-linear current-voltage characteristic with respect to said current whereby said current and said junction can interact to produce said electrical effect. 2. The electronic device according to claim 1 wherein said common area is of the order of 1 micron or less in diameter. 3. An electronic device according to claim 1 wherein said dielectric layer is of the order of 1 nanometer or less thickness, said metal deposits and interposed dielectric layer chosen to provide a barrier potential enabling quantum mechanical electron tunneling across the said potential barrier to predominantely determine junction impedance. 4. An electronic device according to claim 1 wherein said substrate is transparent to said incident radiation and wherein said substrate has a thickness of lambda /4+n lambda where n is an integer and lambda is the wavelength of interest, and a reflective surface immediately below said substrate, said substrate and reflective surface adapted to reflect back radiation in phased relation to radiation at said diode thereby to enhance coupling. 5. An electronic array comprising a multiplicity of devices according to claim 1 wherein said devices are connected in series to each other. 6. The electronic array of claim 5 wherein each of said first and second metal deposits comprises a narrow, elongated antenna, the antennas joined end to end, at least some of the regions of joining comprising junctions having nonlinear current-voltage characteristics. 7. The electronic array of claim 6 wherein a given antenna comprising a first metal deposit is overlapped at each of its ends with the end of an antenna comprising a second metal deposit. 8. The electronic array of claim 6 wherein said first and second metal deposits are of different work function, connections between said antennas along said array alternating between effective junctions and non-responsive connections whereby cancellation effects are avoided. 9. The electronic array of claim 8 wherein said non-responsive connections comprise ohmic connections. 10. The electronic array of claim 8 wherein said non-responsive connections have dielectric between a common area of said first and second metal deposits, said common area being larger with enlarged time constant relative to the common area of said effective junctions. 11. The electronic array of claim 8 wherein the overall length of the series array is chosen to enable establishment of a standing wave, the effective parameters thereof selected so that a current maximum occurs at a first diode, a node at the next, and so on over the overall length of the effective antenna. 12. The electronic device according to claim 1 including means to apply d.c. bias between said first and second metal deposits and wherein said first and second metal deposits are of dissimilar metal, said d.c. bias effective to shift the operating point in the current-voltage characteristic into a region to enhance response. 13. The electronic device according to claim 1 including means to apply d.c. bias between said first and second metal deposits and wherein said first and second metal deposits are of similar metal, said d.c. bias effective to shift the operating point in the current-voltage characteristic away from null. 14. The electronic array of claim 6 wherein each of said antennas has a length n lambda /4 where lambda is the wave length of a frequency of interest and n is an integer chosen to enable effective coupling. 15. The electronic array of claim 6 adapted for parametric processing of optical radiation, said array comprising deposits formed into a phased array relative to an optical frequency of interest. 16. The electronic array of claim 15 comprising a Franklin-Marconi type of antenna geometry which includes straight co-linear antenna sections and re-entrant sections, said co-linear sections constructed to relate to optical radiation in phase and the two legs of each said re-entrant section constructed to cancel the effects of each other and thereby not relate to radiation out of phase with said in phase radiation. 17. The array of claim 16 wherein said junctions are positioned at the extreme excursion of re-entrant sections. 18. The array of claim 16 wherein said junctions are positioned in the middle of colinear antenna sections. 19. The array of claim 5 constructed to respond to a band of radiation frequencies to convert said radiation to electrical energy. 20. The array of claim 19 wherein said dielectric of said junctions has a non-diffusion characteristic at room temperature relative to said first and second metals, said array adapted for use as a broad band detector operative at room temperature. 21. The array of claim 20 wherein said first metal deposit is of tungsten, said second metal deposit is of nickel and said dielectric is tungsten oxide. 22. The device of claim 1 in combination with an integrated optics system for coupling to said device. 23. The device of claim 22 including means for generating an evanescent wave from optical radiation, said device being positioned to be coupled to said evanescent wave. 24. The device of claim 23 including an array in the form of a fishbone antenna. |
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