Optical communications device

An optical communications device comprising a transmission unit for transmitting binary-coded electrical pulse signals, which have a constant bit period and change at a center of the bit period from a high level to a low level or from a low level to high level according to bit data, to an external optical communications device in the form of optical pulse signals, said transmission unit comprising:

• modulation means for producing, at each rising edge of said binary coded electrical pulse signals and at a bit boundary when one of said binary-coded electrical pulse signals remains at a high level across the bit boundary, an electrical pulse signal that is narrow in pulse width;
• and
• electro-optic conversion means for converting each of said electrical pulse signals into optical pulse signals that are narrow in pulse width;
• said transmission unit producing no electrical pulse signal at a falling edge of said binary-coded electrical pulse signals.

An optical communications system comprising first and second optical communications devices:

• said first optical communications device comprising a transmission unit for transmitting binary-coded electrical pulse signals to a second optical communications device in the form of optical pulse signals, said transmission unit comprising:
• modulation means for producing an electrical pulse signal that is narrow in pulse width for each bit in a binary-coded electrical pulse signal when said binary coded electrical pulse signal remains at a high level at the beginning of a succeeding bit period;
• and
• electro-optic conversion means for converting an electrical pulse signal that is narrow in pulse width into an optical pulse signal that is narrow in pulse width;
• said second optical communications device comprising:
• a receiving unit for converting optical pulse signals sent from said first optical communications device into electrical pulse signals, said receiving unit comprising:
• opto-electrical conversion means for converting optical pulse signals that are narrow in pulse width sent from said transmission unit in said first optical communications device into electrical pulse signals that are narrow in pulse width;
• and
• demodulating means responsive to an electrical pulse signal that is narrow in pulse width for recovering an original electrical pulse signal.