Improved bend waveguide design for terahertz transmission

Bending waveguides with 90 corners based on a two-dimensional photonic crystal with metallic cylinders arranged in a square lattice are studied for THz wave guiding. Considering single- and double-line defects, five different designs are investigated and assessed in terms of their transmission performance. A better structure is proposed by increasing the number of rods in the bending arc, thus achieving superior performance of the transmission characteristics in comparison to that of the former five designs. A comparison of the improved bend waveguide with a linear wave-guide shows a significant reduction of the bending losses. Trans-mission levels of up to 98% within a 2.5 THz bandwidth (from 1.2 to 3.7 THz) have been accomplished

Quantum dash mode-locked laser based open-loop optical clock recovery for 160 Gb/s transmission system

We report first demonstration of quantum dash mode-locked laser based open-loop optical clock recovery of 160 Gb/s RZ-OOK after 52 km transmission with 102 fs timing jitter 40 GHz clock and 2 dB BER penalt

Quantum dash mode-locked laser based open-loop optical clock recovery for 160 Gb/s transmission system

We report first demonstration of quantum dash mode-locked laser based open-loop optical clock recovery of 160 Gb/s RZ-OOK after 52 km transmission with 102 fs timing jitter 40 GHz clock and 2 dB BER penalty

320 Gb/s all-optical clock recovery and time demultiplexing enabled by a single quantum dash mode-locked laser fabry-perot optical clock pulse generator

We present the first 320Gb/s all-optical clock recovery by exploiting single Quantum Dash MLL to generate 40GHz synchronized optical clock pulse with 71fs timing jitter. 320Gb/s all-optical demultiplexing operation with 1dB BER penalty was demonstrated

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

A narrowband terahertz signal generated by a unitravelling carrier photodiode (UTC-PD) interfaced with a dual-mode Fabry-Pérot laser diode is demonstrated. A beat tone corresponding to the free spectral range is generated on the UTC-PD, and radiated by a transverse-electromagnetic-horn antenna. A terahertz signal at a frequency of 372 GHz, featuring a linewidth of 17 MHz is recorded by a subharmonic mixer coupled to an electrical spectrum analyzer. All components involved in this experiment operate at room temperature. The linewidth and the frequency of the emitted terahertz wave are analyzed, along with their dependency on dc-bias conditions applied to laser diode

InP-based integrated optical pulse shape : demonstration of chirp compensation

We demonstrate dispersion compensation for highly chirped optical pulses with an ultracompact optical pulse shaper. The device integrates a 20-channel arrayed waveguide grating with 20 phase modulators and 20 semiconductor optical amplifiers on a single chip of 6$,times,$6 ${rm mm}^{2}$. The chip has been realized in an InP-based generic photonic foundry process, which enables a significant reduction in design effort using standardized building blocks

Performance analysis of a photonic integrated interferometer circuit based on silicon-on-insulator

Small footprint photonic integrated interferometer based on silicon-on-insulator platform is reported. A passive interferometer comprising small footprint $$4\times 4$$4×4 and $$2\times 2$$2×2 multi-mode interference (MMI) couplers is designed and tested. The $$4\times 4 \,(2\times 2)$$4×4(2×2) MMIs feature 0.16 dB (0.06 dB) excess loss, 0.22 dB (0.09 dB) power imbalance, and 1.7$$^{\circ }$$∘ (0.12$$^{\circ }$$∘) phase error. An efficient use of the small design area is accomplished by positioning the input and output ports of the passive interferometer along the same side of the chip with a separation of 127\,\upmu \hbox {m}127μm between each other (pitch size). A passive-active interferometer terminated with Ge photodiodes has also been designed and tested. Sinusoidal fitting of the phase differences between output port number 1 and all other output ports are estimated to be under 2$$^{\circ }$$∘ margin, i.e., $$90^{\circ }\pm 1^{\circ },180^{\circ }\pm 1^{\circ }$$90∘±1∘,180∘±1∘ and $$270^{\circ }\pm 1^{\circ }$$270∘±1∘