Design of the Novel Wavelength Triplexer Using Multiple Polymer Microring Resonators

We report about new design of wavelength triplexer using multiple polymer optical microring resonators. Triplexer consists of two downstream wavelength channels operating at 1490 ± 10 nm, 1555 ± 10 nm and one upstream wavelength channel operating at 1310 ± 50 nm. The parallel coupled double ring resonator was used for separation of the optical signal band at 1555 nm and filtered out signal bands 1310 nm and 1490 nm. The serially coupled triple optical microring resonator was used for separation of the optical signal band at 1490 nm and filtered out signal bands 1310 nm and 1555 nm. The design was done by using FullWAVETM software by the finite-difference time-domain method. Simulation showed that optical losses for band at 1555 nm were -3 dB and crosstalk between signal bands 1555 nm and 1490 nm was 24 dB. Calculated optical losses for channel 1490 nm were less than -2.5 dB and signal bands at 1555 nm was filtered out with less than 18 dB loss. The bands at 1310 nm were fully filtered out from both downstream wavelength channels operating at bands 1490 nm and 1555 nm

Unidirectional frequency conversion in microring resonators for on-chip frequency-multiplexed single-photon sources

Microring resonators are attractive for low-power frequency conversion via Bragg-scattering four-wave-mixing due to their comb-like resonance spectrum. However, conversion efficiency is limited to 50% due to the equal probability of up- and down-conversion. Here, we demonstrate how two coupled microrings enable highly directional conversion between the spectral modes of one of the rings. An extinction between up- and down-conversion of more than 40 dB is experimentally observed. Based on this method, we propose a design for on-chip multiplexed single-photon sources that allow localized frequency modes to be converted into propagating continuous-mode photon wave packets using a single operation. The key is that frequency conversion works as a switch on both spatial and spectral degrees of freedom of photons if the microring is interferometrically coupled to a bus waveguide. Our numerical results show 99% conversion efficiency into a propagating mode with a wave packet having a 90% overlap with a Gaussian for a ratio between intrinsic and coupling quality factors of 400

Design and fabrication of a polymer micro ring resonator with laser beam direct write lithography technique

In this article, we describe our work on design and fabrication of a polymer Micro Ring Resonator. This device has been constructed by laser beam direct write lithography technique (LBL).We used ORMOCORE photoresist for fabricating a micro ring resonator due to its very low losses at wavelengths 1550 nm and 1300 nm and also used a tapered fiber to couple light into the bus waveguide and received the signal from the output port of the waveguide by using another tapered fiber which the gap between bus waveguide and ring waveguide is then filled with nitrobenzene liquid by micropipette (which has large dependence of the refractive index on temperature) for increasing efficiently coupling to ring waveguide. The signal has been monitored by using an optical spectrum analyze .This micro ring resonator in the laterally coupled geometry for wavelength 1550 (nm) have band width (Δλ) 0.3 (nm), free spectral range of 0.8 (nm) and finesse of 2.6

Coupling ideality of integrated planar high-Q microresonators

Chipscale microresonators with integrated planar optical waveguides are useful building blocks for linear, nonlinear and quantum optical devices. Loss reduction through improving fabrication processes has resulted in several integrated micro resonator platforms attaining quality (Q) factors of several millions. However only few studies have investigated design-dependent losses, especially with regard to the resonator coupling section. Here we investigate design-dependent parasitic losses, described by the coupling ideality, of the commonly employed microresonator design consisting of a microring resonator waveguide side-coupled to a straight bus waveguide. By systematic characterization of multi-mode high-Q silicon nitride microresonator devices, we show that this design can suffer from low coupling ideality. By performing full 3D simulations to numerically investigate the resonator to bus waveguide coupling, we identify the coupling to higher-order bus waveguide modes as the dominant origin of parasitic losses which lead to the low coupling ideality. Using suitably designed bus waveguides, parasitic losses are mitigated, and a nearly unity ideality and strong overcoupling (i.e. a ratio of external coupling to internal resonator loss rate > 9) are demonstrated. Moreover we find that different resonator modes can exchange power through the coupler, which therefore constitutes a mechanism that induces modal coupling, a phenomenon known to distort resonator dispersion properties. Our results demonstrate the potential for significant performance improvements of integrated planar microresonators, achievable by optimized coupler designs.Comment: 8 pages, 3 figures, 1 tabl