Patent ID: 6904209

Claim:
An optical communication module comprising: a bench with a top and a roughened bottom coated with a photoabsorbent resin, adhesive, pigment, or paint; a lightwaveguide having a core of a higher refractive index and a cladding of a lower refractive index and being formed upon the top of the bench; an optical fiber having a front end joined to the lightwaveguide for transmitting signal beams of different wavelengths λ 1 in λ 2 both directions; a light emitting device mounted on the bench behind a rear end of the lightwaveguide for making a transmitting signal beam of a wavelength λ 1 for which the bench is transparent; a wavelength selective filter mounted on the bench across the lightwaveguide for separating λ 1 beam and λ 2 beam; and a photodetecting device with sensitivity for both λ 1 and λ 2 mounted along the lightwaveguide for receiving λ 2 beam reflected by the wavelength selective filter.