Patent ID: 6850713
Filing Date: 2005-02-01
Classification: H04B,H04L

Abstract:
1. An optical single sideband transmitter comprising a laser source, a first optical module, a second optical module, and an optical filter, wherein said transmitter acquires RZ (return-to-zero) modulated light that is single-sidebanded by the (1) or (2) indicated below: (1) The laser light output from said laser source is supplied to said first optical module, via two optical paths, and converted into a single-sideband periodic optical pulse train using two sine wave electrical signals that are phase shifted by 90 degrees from each other; the single-sideband periodic optical pulse train, which is the output from said first optical module, is applied to said second optical module and intensity modulated by a digital information signal; and, the resulting output is then single-sidebanded by said optical filter; and (2) The laser light, which is the output from said laser source, is applied to said second optical module and subjected to NRZ (nonreturn-to-zero) intensity modulation by said digital information signal; a NRZ intensity modulated optical signal, which is the output from said second optical module, is applied to said first optical module, via two optical paths, and converted into a RZ optical signal with single sidebanded optical carriers using the two sine wave electrical signals that are phase shifted by 90 degrees from each other; and, the resulting output is then single-sidebanded by said optical filter.