Patent ID: 7218829
Filing Date: 2007-05-15
Classification: G02B

Abstract:
1. An optical transmission module for transmitting signal light to a transmission path, the optical transmission module comprising: a drive unit for outputting a modulation signal; a signal light output unit for performing electrical/optical conversion on the modulation signal outputted from the drive unit to generate signal light with a predetermined extinction ratio, and for outputting the generated signal light; and a loss generator for attenuating light propagating between the signal light output unit and the transmission path by a predetermined attenuation factor, thereby attenuating the signal light outputted from the signal light output unit by the predetermined attenuation factor, and for outputting the attenuated signal light to the transmission path, wherein the predetermined attenuation factor of the loss generator is set based on at least an extinction ratio of the signal light output unit, and the transmission path has formed thereon a reflection portion having a predetermined reflection coefficient, and if the predetermined reflection coefficient of the reflection portion is A, the extinction ratio of the signal light output unit is B, a signal Q factor of the signal light is Q, a tolerable penalty for a bit error rate is D, and the predetermined attenuation factor of the loss generator is C, the attenuation factor C is set as follows: