Abstract: An optical transmission system is disclosed wherein a multiplexed analog signal is supplied to a laser diode to modulate the intensity of a long-wavelength laser beam. A single mode optical fiber transmission medium has a first inclined end face at a proximal end and a second inclined end face at a distal end. The laser beam is coupled to the proximal end of the transmission medium by a coupling means including a single mode optical fiber connecting medium having one end connected to the laser diode and an opposite end having a third inclined end face complementary to the first inclined end face and a coupler for coupling the first and third inclined end faces in abutment relation.

Abstract: A DPCM coding apparatus adapted for directly coding a composite color television signal is disclosed which carries out a so-called two-dimensional prediction using horizontal and vertical signals from a predetermined earlier period as predict value for DPCM while taking the color sub-carrier wave into consideration. The two-dimensional prediction allows immediate restoration after dropout of the coded signal should this occur.