We propose fast and robust mode conversion in multimode waveguides based on Lewis–Riesenfeld invariant theory. The design of converters using the driving for dynamical is discussed. Computer-generated planar holograms are used to mimic shaped pulses states three-level quantum systems. show that invariant-based inverse engineering scheme reduces converter length as compared common adiabatic scheme.

A short and broadband silicon asymmetric Y-junction two-mode (de)multiplexer is proposed simulated. An adiabaticity parameter suitable for high index-contrast waveguides defined. The fast quasiadiabatic dynamics protocol used to homogeneously distribute over the device length. This limits power coupled into unwanted waveguide eigenmode under a fixed value along propagation. 16 μm long mode with crosstalk < -34 dB obtained. Simulations show that optical bandwidth as large 300 nm (1400 ~ 1700...

We propose short and robust directional couplers designed by shortcuts to adiabaticity, based on Lewis-Riesenfeld invariant theory. The design of is discussed combining invariant-based inverse engineering perturbation error sensitivity the coupler minimized optimizing evolution dynamical with respect coupling coefficient/input wavelength variations. proposed devices are verified beam propagation simulations.

Compact silicon mode (de)multiplexers based on asymmetrical directional couplers are designed using shortcuts to adiabaticity. The coupling coefficient and propagation constants mismatch engineered optimize the device robustness. Simulations show that devices broadband have large fabrication tolerance.

We propose an ultrashort and broadband silicon mode-conversion polarization splitter-rotator (PSR) consisting of a taper Y-junction both designed by the fast quasiadiabatic dynamics (FAQUAD). The FAQUAD is used to homogeneously distribute adiabaticity over length PSR, providing shortcut at shorter device length. total PSR 39.2 μm. For wavelength range from 1.5 μm 1.6 μm, exhibits good performance with > 88% transmission 11.4 dB extinction ratio (ER). Simulations also show that devices have...

A shortcut to adiabatic mode conversion in multimode waveguides using optical analogy of stimulated Raman passage is investigated. The design converters the scheme discussed. Computer-generated planar holograms are used mimic shaped pulses speed up quantum systems based on transitionless driving algorithm. coupling properties analyzed coupled theory and beam propagation simulations. We show reduced device length as compared common scheme. Modal evolution shortened indeed follows eigenmode...

Sending multiple messages on qubits encoded in different vibrational modes of cold atoms or ions along a transmission waveguide requires us to merge first and then separate the at input output ends. Similarly, can be stored trap separated later. We design fast splitting harmonic into an asymmetric double well so that initial ground state becomes one two final wells, excited other well. This might done adiabatically by slowly deforming trap. speed up process inverse engineering...

We propose a compact and high conversion efficiency asymmetric Y junction mode multiplexer/demultiplexer for applications in on-chip mode-division multiplexing. Traditionally, sorting is achieved by adiabatically separating the arms of junction. shorten device length using invariant-based inverse engineering achieve better than adiabatic device.

Shortcuts to adiabaticity, originally developed in the context of quantum control, are powerful tools for design high coupling efficiency, robust, and short coupled-waveguide devices. The counterdiabatic protocol cancels unwanted system evolution by addition a term. invariant-based inverse-engineering approach designs using decoupled eigenstates Lewis–Riesenfeld invariant. single-shot shaped-pulse technique directly parameterizes solution coupled-mode equation. Starting from protocol, we...

We propose a fast quasiadiabatic approach to the design of optical waveguide devices.This distributes system adiabaticity homogeneously over device length, thus providing shortcut at shorter length.A mode sorting asymmetric Y junction is designed by redistributing conventional linearly separating junction.Simple procedures for devices are outlined, and features large bandwidth length than junction.The proposed verified with beam propagation simulations.A conversion efficiency larger 99%...

Conventional strategies to design adiabatic coupled-waveguide devices focus on optimizing the system adiabaticity but can only guarantee 100% efficiency at specific lengths. We establish a simple technique allowing optimization of device and ensuring coupling/conversion any physically realizable length. Specifically, we use shortcuts-to-adiabaticity represent state precisely engineer evolution be as close possible. Smooth parameters are derived for devices, which feature good robustness...

In recent years, the concept of shortcuts to adiabaticity (STA), originally developed for speeding up slow adiabatic state evolution in quantum systems, has found numerous applications guided-wave optics. Optical waveguides, enabled by advanced fabrication technologies, provide an ideal platform implement STA protocols terms geometry variations; moreoever, development short and robust waveguide components, with beam couplers, splitters, mode converters, (de)multiplexers, polarization...

We report a 2×2 broadband and fabrication tolerant mode-evolution-based 3 dB coupler based on silicon-on-insulator rib waveguides. The operating principle of the is adiabatic evolution local eigenmodes. key element device an adiabatically tapered mode region, which converts two dissimilar waveguides into identical Contrary to conventional designs using linear taper function where adiabaticity uneven during evolution, we use fast quasiadiabatic approach homogenize device, leading shortcut...

We review potential applications of third-harmonic generation (THG) in polymer composites to implement optical image processing at the eye-safe and technologically relevant telecommunication bands. discuss two examples, time-gated imaging through scattering media, recognition using Fourier-based techniques, where THG a composite offers significant advantages over typical holographic that it produces signals are non-degenerate frequency space, allows development compatible with low-cost...

In this paper, we propose the use of invariant based shortcuts to adiabaticity for analysis directional couplers. By describing dynamical evolution system using eigenstates through new parameterizations, stability against errors in coupling coefficient and propagation constants mismatch is connected with parameters, which can be linked back parameters inverse engineering. The merits limitations conventional tapered coupler designs various window functions are obtained analysis. We then an...

Variable power splitting ratio 2x2 MMI couplers using multimode waveguide holograms are analyzed. Theoretical analysis shows that variable ratios can be obtained with surface relief on fixed dimensions. Devices paired-imaging lengths designed a silicon-on-insulator (SOI) platform. Beam propagation simulations used to verify matrix theory and investigate proposed device performance. Fabrication tolerance of the is also

The goal in designing mode-evolution based devices is to realise short and high-fidelity components. counterdiabatic protocol coherent quantum state control can be used cancel unwanted coupling between adiabatic modes mode evolution but not directly realisable the coupled-waveguide system. By finding alternative coupled-mode equations that links same interaction picture dynamical equation as via unitary transformations, we have derived a universal formalism for design of devices. Starting...

We propose fast and robust beam coupling in a three waveguide directional coupler based on Lewis-Riesenfeld invariant theory. This method provides shortcuts to optical couplers coherent tunneling adiabatic passage of photons. The design performance using the invariant-based inverse engineering are discussed. Beam is achieved by evolution eigenmodes invariant. show that scheme reduces length as compared with common scheme. device against coefficient variations has broadband characteristics.

We design and fabricate a series of broadband silicon arbitrary power splitters with various split ratios using shortcuts to adiabaticity. In this approach, the system evolution is designed decoupled states, desired are guaranteed by boundary conditions. Furthermore, evolutions optimized be as close adiabatic states possible, thus enhancing robustness wavelength fabrication variations. The devices more compact then conventional designs. Fabricated show response for wide range from 1.47 1.62...

We prepared urchin-like micron-sized ZnO cavities with high optical quality by oxidizing metallic Zn and proposed the mechanism that resulted in growth of microstructures. The photoluminescence spectra microstructures had a predominant excitonic emission at room temperature. lasing properties were investigated systematically through excitation power- size-dependent measurements. results showed low threshold factors could be achieved because reflectivity reflectors formed tapered nanowires....

We propose a method for the robust splitting of light between two outer waveguides in three-waveguide system by mode evolution. Arbitrary power ratio is achieved engineering spacings middle waveguide and waveguides. Coupling into suppressed adiabatic elimination scheme. To speed up passage effective two-mode involving only waveguides, we introduce fast quasi-adiabatic dynamics protocol, leading to shortcut adiabaticity. Using proposed scheme, splitters with various ratios including, 10/90,...

Integration of holograms into multimode waveguides allows the implementation arbitrary unitary mode transformations and matrix-vector multiplication. Theoretical analysis is used to justify a design approach implement specific functions in these devices. Based on this approach, compact mode-order converter, Hadamard transformer, spatial pattern generator-correlator are proposed analyzed. Beam propagation simulations verify theoretical calculations address bandwidth, scalability, fabrication...

We propose and describe mode converter/splitter based on optical analogy of multistate stimulated Raman adiabatic passage in multimode waveguides. Computer-generated planar holograms are used to implement the coupling coefficients that mimic pulses transfer among quantum states atoms molecules. The properties waveguides analyzed using coupled-mode theory shown resemble process. Key features systems illustrated with theoretical calculations numerical examples. Mode converter splitter designed...

We discuss mode conversion and splitting in multimode waveguides based on Lewis-Riesenfeld invariant theory. The design of converters/splitters using the dynamical is discussed. Closed form expressions for modal power at output converter/splitter are derived. Various approaches discussed assessed by beam propagation simulations. show that invariant-based engineering scheme reduces device length as compared to common adiabatic scheme.