Abstract: An optical time-division multiplexer in which the phase difference between two optical signals to be used for the synthesis of an output optical signal thereof is maintained at a constant value, regardless of variations in accuracy of the manufacture thereof. Thereby, stable output optical signals are obtained at all times. The optical time-division multiplexer includes first and second optical modulators to respectively output first and second optical modulation signals synchronized with a clock signal and corresponding to different time slots, respectively; an optical coupler for performing time-division multiplexing of the first and second optical modulation signals respectively outputted by the first and second optical modulators; and an optical-phase adjusting unit to receive at least one of the first and second optical modulation signals and to regulate an optical phase of the inputted optical signal.

Abstract: A request for inputting of, for example, a character string of a retrieval item, is issued to an operator by an input request section of an item processing section via a pattern/character editing section and a display operating section; and a request for specification of a to-be-retrieved pattern is issued to the operator by a specification request section of a pattern specifying section. A retrieval processing section retrieves a data base for the retrieval item obtained in the item processing section and the to-be-retrieved pattern obtained in the pattern specifying section. The retrieval result of the data base by the retrieval processing section is converted into a character string corresponding to data derived as the retrieval result by a character creation section of a writing processing section, arranged in position corresponding to an input retrieval item in the drawing by a character arranging section of the writing processing section, and written into the drawing data.