Shoulin Jiang

Circular-core single-mode polymer waveguide for high-density and high-speed optical interconnects application at 1550 nm

We demonstrate circular-core 1550 nm single-mode polymer waveguides with a graded-index profile fabricated by commercially available UV-curable epoxies using so-called mosquito method. The relative index difference ∆n of the waveguides was designed to be 0.46% in order to guarantee both single-mode operation and good compatibility with standard single-mode fiber. Accurate refractive index tuning of monomer for core construction was realized by mixing the core and cladding epoxies properly. The core pitch of the waveguides was chosen to be 50 μm to satisfy the requirements for high-density on-board optical interconnects. Both the optical characteristics and high-speed performances of the waveguides were comprehensively studied at 1550 nm. The measured transmission and coupling loss are 0.79 dB/cm and 0.78 dB, respectively. The waveguides exhibit an inter-channel crosstalk as low as -45 dB, and a 3 dB misalignment tolerance larger than ± 4 μm on the input and output facet in both horizontal and vertical directions. NRZ signal at a data rate of 25 Gb/s was transmitted over a 10 cm-long waveguide. There is no obvious degradation on the eye diagram due to the insertion of the waveguide and error free transmission was successfully obtained. Our results imply that the fabricated single-mode polymer waveguides have good potential in high-density and high-speed optical interconnects application.

Real-time locating and speed measurement of fibre fuse using optical frequency-domain reflectometry

We propose and experimentally demonstrate real-time locating and speed measurement of fibre fuse by analysing the Doppler shift of reflected light using optical frequency-domain reflectometry (OFDR). Our method can detect the start of a fibre fuse within 200 ms which is equivalent to a propagation distance of about 10 cm in standard single-mode fibre. We successfully measured instantaneous speed of propagating fibre fuses and observed their subtle fluctuation owing to the laser power instability. The resolution achieved for speed measurement in our demonstration is 1 × 10−3 m/s. We studied the fibre fuse propagation speed dependence on the launched power in different fibres. Our method is promising for both real time fibre fuse monitoring and future studies on its propagation and termination.

Ring-assisted 7-LP-mode Fiber with Ultra-low Inter-mode Crosstalk

We propose novel ring-assisted 7-LP-mode fiber with ultra-low inter-mode crosstalk without obvious degradation on other characteristics by improving the minimum value of

Orientation-insensitive mode-selective coupler for two-mode transmission at 850 nm using standard SMF

\Delta \mathrm{n}_{\text{eff}}

Coupling analysis of non-circular-symmetric modes and design of orientation-insensitive few-mode fiber couplers

for 70%. We experimentally verified feasibility of our method in 4-LP-mode fiber.

Observation of Fiber Fuse Propagation Speed Oscillation Due to Inter-mode Interference in Two-mode Fibers

We demonstrate the design of an orientation-insensitive mode-selective coupler working as a DeMUX for two-mode transmission at 850 nm using SSMF. The mode extinction ratios of LP01/LP11 and LP11/LP01 are above 12.6 dB and 21.2 dB in the band of 845 to 855 nm.