Cost-effective equalization of electro-optic frequency combs in a Sagnac interferometer.

We present a cost-effective electro-optic frequency comb generation and equalization method using a single phase modulator inserted in a Sagnac interferometer layout. The equalization relies on the interference of comb lines generated in both clockwise and counter-clockwise directions. Such a system is capable of providing flat-top combs with flatness values comparable with other approaches proposed in literature, yet offering a simplified synthesis and reduced complexity.

Arbitrarily high time bandwidth performance in a nonreciprocal optical resonator with broken time invariance.

Most present-day resonant systems, throughout physics and engineering, are characterized by a strict time-reversal symmetry between the rates of energy coupled in and out of the system, which leads to a trade-off between how long a wave can be stored in the system and the system's bandwidth. Any attempt to reduce the losses of the resonant system, and hence store a (mechanical, acoustic, electronic, optical, or of any other nature) wave for more time, will inevitably also reduce the bandwidth of the system. Until recently, this time-bandwidth limit has been considered fundamental, arising from basic Fourier reciprocity.

49.6 Gb/s direct detection DMT transmission over 40 km single mode fibre using an electrically packaged silicon photonic modulator.

We present the characterization of a silicon Mach-Zehnder modulator with electrical packaging and show that it exhibits a large third-order intermodulation spurious-free dynamic range (> 100 dB Hz). This characteristic renders the modulator particularly suitable for the generation of high spectral efficiency discrete multi-tone signals and we experimentally demonstrate a single-channel, direct detection transmission system operating at 49.6 Gb/s, exhibiting a baseband spectral efficiency of 5 b/s/Hz.