A data transmission system comprising: an optical cable comprising a gigabit optical fiber; and first through fourth dual-wavelength single-fiber bidirectional transceivers (Trx#1-Trx#4) each comprising an optical filter, a laser disposed to transmit light through the optical filter, and a photodetector disposed to receive light reflected by the optical filter, wherein: the laser and photodetector of the first transceiver are respectively optically coupled to the photodetector and laser of the second transceiver, and the laser and photodetector of the third transceiver are respectively optically coupled to the photodetector and laser of the fourth transceiver by way of the gigabit optical fiber; the laser of the first transceiver emits light having a first wavelength, the laser of the second transceiver emits light having a second wavelength, the laser of the third transceiver emits light having a third wavelength, and the laser of the fourth transceiver emits light having a fourth wavelength; the optical filters of the first and second transceivers pas light having the first wavelength and reflect light having the second wavelength, and the optical filters of the third and fourth transceivers pass light having the third wavelength and reflect light having the fourth wavelength; and a first glass optical fiber coupler that optically couples a single fiber of the first and third transceivers to one end of the gigabit optical fiber; and a second glass optical fiber coupler that optically couples a single fiber of the second and fourth transceivers to another end of the gigabit optical fiber. an optical cable comprising a gigabit optical fiber; and first through fourth dual-wavelength single-fiber bidirectional transceivers (Trx#1-Trx#4) each comprising an optical filter, a laser disposed to transmit light through the optical filter, and a photodetector disposed to receive light reflected by the optical filter, wherein: the laser and photodetector of the first transceiver are respectively optically coupled to the photodetector and laser of the second transceiver, and the laser and photodetector of the third transceiver are respectively optically coupled to the photodetector and laser of the fourth transceiver by way of the gigabit optical fiber; the laser of the first transceiver emits light having a first wavelength, the laser of the second transceiver emits light having a second wavelength, the laser of the third transceiver emits light having a third wavelength, and the laser of the fourth transceiver emits light having a fourth wavelength; the optical filters of the first and second transceivers pas light having the first wavelength and reflect light having the second wavelength, and the optical filters of the third and fourth transceivers pass light having the third wavelength and reflect light having the fourth wavelength; and a first glass optical fiber coupler that optically couples a single fiber of the first and third transceivers to one end of the gigabit optical fiber; and a second glass optical fiber coupler that optically couples a single fiber of the second and fourth transceivers to another end of the gigabit optical fiber. the laser and photodetector of the first transceiver are respectively optically coupled to the photodetector and laser of the second transceiver, and the laser and photodetector of the third transceiver are respectively optically coupled to the photodetector and laser of the fourth transceiver by way of the gigabit optical fiber; the laser of the first transceiver emits light having a first wavelength, the laser of the second transceiver emits light having a second wavelength, the laser of the third transceiver emits light having a third wavelength, and the laser of the fourth transceiver emits light having a fourth wavelength; the optical filters of the first and second transceivers pas light having the first wavelength and reflect light having the second wavelength, and the optical filters of the third and fourth transceivers pass light having the third wavelength and reflect light having the fourth wavelength; and a first glass optical fiber coupler that optically couples a single fiber of the first and third transceivers to one end of the gigabit optical fiber; and a second glass optical fiber coupler that optically couples a single fiber of the second and fourth transceivers to another end of the gigabit optical fiber.