公开(公告)号：JPH05191352A

公开(公告)日：1993-07-30

申请号：JP19741892

申请日：1992-07-02

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： RITSUKARUDO KARUBAANI ,  RENAATO KAPONI ,  JIYUZETSUPE MAROONE

IPC: G02F2/00 ,  H04B10/04 ,  H04B10/06 ,  H04B10/135 ,  H04B10/142 ,  H04B10/152

Abstract: PURPOSE: To transmit a signal including two orthogonal modulation components with different frequencies for each bit by orthogonally setting polarized state of a light beam radiated from two light sources to correspond to each bit of information signal and synthesizing the polarized state. CONSTITUTION: The light beam radiated from a laser 1 which is the linearly polarized light beam is transmitted to a polarized beam splitter 7. In addition, the light beam transmitted from a laser 2 with a half-wavelength plate 8 is received by a reflecting surface of the splitter 7. Therefore, the light beam is polarized in a surface orthogonally crossed with a light receiving surface of the light beam radiated from the laser 1. In addition, a single light beam obtained by synthesizing two light beams is transmitted to a mode fiber 12 with a lens system 11 by the splitter 7. The light beam extracted from the fiber 12 is paralleled by a lens 13, supplied to a correcting part 14 and the light beam outputted from the fiber 12 ordinarily formed in ellipse is returned to a linearly polarized state. Consequently, the orthogonal polarization components with different frequencies are transmitted on a line for each bit.

公开(公告)号：JPH05191353A

公开(公告)日：1993-07-30

申请号：JP19741992

申请日：1992-07-02

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： RITSUKARUDO KARUBAANI ,  RENAATO KAPONI ,  JIYUZETSUPE MAROONE

IPC: G02F2/00 ,  H04B10/04 ,  H04B10/06 ,  H04B10/135 ,  H04B10/142 ,  H04B10/152

Abstract: PURPOSE: To constitute a system transmitter or a local oscillator by two sources of light beam by synthesizing orthogonally polarized light beams generated from two independent sources of light beam and with different frequencies each other. CONSTITUTION: Two semiconductor lasers 1, 2 approximated to each other at the most are connected to a binary data flow source 3 and the two lasers 1, 2 are frequency modulated by the flow source 3. Then signals from the flow source 3 are supplied to controllers 4, 5 of the laser 1, 2 and each signal is superimposed on DC exciting voltage VB1, VB2. Each laser is oscillated by the signal with four frequencies corresponding to a logic value of a binary signal. In this case, the linearly polarized light beam generated from the laser 1 is transmitted to a polarized beam splitter 7, light is received on a transmitted surface and the light beam from the laser 2 is received on a reflecting surface. The light beam becomes the orthogonally polarized light beams with different frequencies each other, the light beams are synthesized and transmitted onto a transmission line 12. Then the linear polarization rotating by 360 degrees is obtained and the system transmitter or the local oscillator is constituted.

公开(公告)号：JPH02275411A

公开(公告)日：1990-11-09

申请号：JP857590

申请日：1990-01-19

Applicant: CSELT CENTRO STUDI LAB TELECOM

Inventor： RIKARUDO KARUBUANI ,  RENATO KAPONI ,  JIYUZETSUPE MAROONE

IPC: G02F1/03 ,  G02F1/035 ,  G02F1/31 ,  G02F1/313 ,  H04B10/135

Abstract: PURPOSE: To obtain a polarized light modulator having simple structure, compact size and high speed operation by receiving light from a 1st or 2nd passage by a 1st or 2nd input part, transmitting the received light to an output part and changing the polarized state of a modulation signal consisting of output light in accordance with the level of a data signal. CONSTITUTION: Horizontally polarized light oscillated in a horizontal surface is inputted from an input part P1 to a switch 6 and outputted from an output part P2 or P4. In this case, the light is outputted from the output part P2 or P4 in accordance with the logical value '0' or '1' of a sequence bit outputted from an encoder 7. The state of polarized light outputted from the output part is always the same as polarized light state of a signal inputted to the input part of the switch 6. Namely vertically polarized light or horizontally polarized light is outputted in accordance with the logical value '0' or '1' of the sequence bit of information. The obtained polarized modulation signal is demodulated by a receiver in a communication system. Consequently the polarized light modulator having simple and compact size and extremely short switching time can transmit a signal at a transmission speed of G bits/sec.