Optical comb for generation of a continuously tunable coherent THz signal from 122.5 GHz to >2.7 THz.

We present a continuously tunable optical frequency comb generator (OFCG), with comb lines spanning over 3.8 THz which, to the best of our knowledge, is the widest span yet reported for a single-phase modulator OFCG system. The line spacing, exactly determined by a microwave reference, can be continuously tuned and, by heterodyning two lines, enables the generation of a continuously tunable electrical signal from 122.

Foundry fabricated photonic integrated circuit optical phase lock loop.

This paper describes the first foundry-based InP photonic integrated circuit (PIC) designed to work within a heterodyne optical phase locked loop (OPLL). The PIC and an external electronic circuit were used to phase-lock a single-line semiconductor laser diode to an incoming reference laser, with tuneable frequency offset from 4 GHz to 12 GHz. The PIC contains 33 active and passive components monolithically integrated on a single chip, fully demonstrating the capability of a generic foundry PIC fabrication model.

Terahertz generation mechanism in nano-grating electrode photomixers on Fe-doped InGaAsP.

We report the generation mechanism associated with nano-grating electrode photomixers fabricated on Fe-doped InGaAsP substrates. Two different emitter designs incorporating nano-gratings coupled to the same broadband antenna were characterized in a continuous-wave terahertz (THz) frequency system employing telecommunications wavelength lasers for generation and coherent detection. The current-voltage characteristics and THz emission bandwidth of the emitters is compared for different bias polarities and optical polarisations.

High temperature operation of athermal widely tuneable laser with simplified wavelength control for WDM-PON systems.

A simplified control system is described which uses only three point calibration to maintain the wavelength of the ITU channels of an uncooled DS-DBR laser, spaced at 50GHz, over the full C-band. Wavelength is controlled mode-hop free over a temperature range of 45° to 80°C.