Breaking Data Speed Records on Optical Fiber
Given the ever-increasing data traffic, miniaturized optical transmitters and receivers that operate with high-order multi-level modulation formats and faster data transmission rates are critical. Researchers have developed a new compact indium phosphide (InP)-based coherent driver modulator (CDM) that achieves a record high baud rate and transmission capacity per wavelength.
Such applications as video distribution and web conferencing services are widespread. Now, to access new services, data rates of optical transmission systems must increase. Developing an optical transmitter covering the C+L band in a single module allows for flexible network operation while reducing equipment costs. The research will be presented by NTT Innovative Devices Corporation in Japan at this year’s OFC, March 24 – 28, 2024, at the San Diego Convention Center.
With higher baud rates, the bandwidth of the modulation signal increases, and fewer channels can transmit in the conventional C-band. This makes extending the wavelength bandwidth from the C-band to the L-band even more critical.
Modulators made from semiconductor InP feature excellent optical and radio frequency characteristics; their strong wavelength dependence makes it difficult to extend wavelength range. The researchers developed a novel InP modulator chip with an optimized semiconductor layer and waveguide structure able to operate over a wide wavelength range, achieving the world’s first CDM with an InP modulator chip that can transmit in C+L band in an 11.9 × 29.8 × 4.35 mm3 package.
The new CDM exhibited an electro-optic 3-dB bandwidth of more than 90 GHz, an insertion loss at maximum transmission of less than 8 dB, and an extinction ratio of 28 dB or more. According to the study authors, this is the first time an InP-based CDM has been shown to operate in the C+L bands, and the world record’s transmission capacity per wavelength has been reported for a CDM
Alpha samples of the CDM are ready for shipping from the NTT Innovative Devices Corporation.
