| 摘要 |
<p>1517013 Semiconductor devices NORTHERN ELECTRIC CO Ltd 14 Aug 1975 [17 Sept 1974] 33940/75 Heading H1K The light emitted from a forward biased photo-diode 36 junction formed in one of the semiconducting layers 32 of heterostructures 41 has a wavelength greater than the absorption edge for layer 32 in regions 41, which allows the flight intensity to be modulated by the electroabsorption occurring on reverse biasing the regions 41. The heterostructure comprises n- and p-type layers 31, 33 of GaAlAs, and n- and p-type layers 32, 33 of GaAs grown by sequential deposition on a substrate 30, using liquid phase epitaxy. Isolation of the photo-diode region 36 is achieved by selective etching. The Au electrode 38 and the AuGe electrode 42 are formed by vacuum deposition. Alternative structures may combine layers 33 and 34. In an application of the device to an AND logic element, Fig. 13 (not shown), a second diode is used as a detector which responds only when two simultaneous signals are applied to two modulators between the emitter and detector.</p> |
