Linear PD/LD module, linear PD/LED module, linear LD/PD module, linear LED/PD module and linear PD module

US5787215A · kind A · utility

Assignee

• Sumitomo Electric Industries, Ltd. · JP

Inventors

• Yoshiki Kuhara · Osaka, JP
• Naoyuki Yamabayashi · Yokohama, JP
• Yasuhiro Iguchi · Itami, JP
• Yasushi Fujimura · Osaka, JP
• Hiromi Nakanishi · Osaka, JP

Key dates

• Filing date: Nov 13, 1996
• Grant date: Jul 28, 1998
• Expiry date: Nov 13, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F55/25

Abstract

WDMs have been used to separate a plurality of signals spatially by the difference of wavelengths in prior bidirectional multiwavelength optical communication network. For excluding WDMs, linear PD/LD modules adopt eigen-wavelength photodiodes sensing only the light of an eigen wavelength but allowing all the wavelengths longer than the eigen wavelength. An n-member PD/LD module aligns (n-1) eigen wavelength photodiodes, PD1, PD2, PD3, . . . , PDn-1 of .lambda.1, .lambda.2, .lambda.3, . . . ,.lambda.n-1 and an LD of .lambda. n which satisfy inequalities .lambda.1<.lambda.2<.lambda.3 <. . . <.lambda. n in series on a beam line in the order of increasing the eigen wavelengths. Otherwise, an n-member PD/LED module aligns k eigen wavelength PDs of .lambda.1, .lambda.2, .lambda.3, . . . , .lambda.k and (n-k) LEDs emitting light of different wavelengths of .lambda.k+1, .lambda.k+2, .lambda.k+3, . . . .lambda. n on the beam line in the same order. On the contrary, an n-member LD/PD module aligns a .lambda.1 laser and (n-1) eigen-wavelength photodiodes PD2, PD3, . . . , PDn of .lambda.2, .lambda.3, . . . , .lambda.n in series on a beam line ( .lambda.1<.lambda.2<.lambda.3 <. . . <.lambda.n…