Investigation on the origin of terahertz waves generated by dc-biased multimode semiconductor lasers at room temperature

A technique to measure a terahertz wave generated by spectrum tailored Fabry–Pérot lasers (FP) is assessed. A dc-biased and 25 °C temperature controlled FP is probed by a continuous wave signal, tuned at 20 nm away from its lasing modes. With a 0.02 nm resolution optical spectrum analyzer (OSA), the terahertz generated signal frequency is measured from the interval between the probe and its side-band modulations. The terahertz waves emitted by these FPs are measured at 370±5 GHz and at 1.157±0.005 THz, respectively, within a precision set by our OSA. The origin of the terahertz wave is due to passive mode-locked through intracavity four-wave-mixing processes

Photonic integrated interferometer based on silicon-on-insulator nano-scale MMI couplers

A photonic integrated interferometer based on silicon-on-insulator 4×4 and 2×2 nano-scale MMI couplers is designed and characterized. Small footprints MMIs featuring 0.28 dB excess loss and 2.85-degrees phase error in a 20 nm span are reported

Narrowband terahertz signal generator based on dual-mode Fabry-Pérot semiconductor laser and uni-travelling carrier photodiode

International audienc

Electro-optic up-conversion mixer amenable to photonic integration

International audienceA novel electro-optical up-conversion mixer architecture comprising four electro-optical phase modulators situated in the arms between an interconnected 1 × 4 distribution tree and a complementary 4 × 2 combination tree is proposed. The distribution and combination trees are based on multi-mode interference couplers (MMI). The novelty lies in the use of the intrinsic phase relations between the MMI ports to realize a broadband and free of drift design requiring no static phase shift elements. A transfer-matrix approach is followed to represent the main building blocks in the proposed design, and hence to describe the operation of the entire optical up-conversion mixer. The concept is demonstrated by computer simulations. A single side-band modulation with carrier suppression is obtained at the output of the proposed architecture, which is in agreement with the analytical development. Scenarios considering both ideal and imperfect power balances and phase relations in the MMIs, as well as imperfect phase relations of the electrical drives to the phase modulators are analyzed