4×4 polymer thermo-optic directional coupler switch at 1.55μm

An integrated 4×4 polymer thermo-optic switch at 1.55 μm is demonstrated for the first time. A fibre to fibre insertion loss of 10 dB, and extinction ratios of 17.5-19.5 dB were measured. The polarisation sensitivity was typically less then 0.5 dB and the response time was less then 1 ms. The electrical power consumption was found to be 70 mW per single switch     

4 × 4 optical-gate matrix switch

An optical gate-based matrix switch is proposed and a switching function in a 4 × 4 experimental switch is demonstrated. The experimental switch is composed of fiber-type splitters, a lantham-modified lead zirconate-titanate solid solution (PLZT) optical-gate array, and fiber-type combiners. The switch has a broad bandwidth of 400 Mbit/s for nonreturn-to-zero (NRZ) optical signal transmission. A possible maximum matrix size is discussed theoretically based on optical power level and optical crosstalk.     

Hybrid polymer/silica vertical coupler switch with <-32 dBpolarisation-independent crosstalk

A modified hybrid polymer/silica 1×2 vertical coupler switch (VCS) with a polymer gap layer and a refractive index contrast of 0.008 has been designed, fabricated and characterised. The VCS exhibits low loss, low crosstalk, low switching power, and polarisation insensitivity. Using the 1×2 VCS as a building block, a 1×8 VCS matrix has been implemented     

Linear crosstalk in 4×4 semiconductor optical amplifier gateswitch matrix

We report a comprehensive crosstalk investigation of a packaged InGaAsP/InP 4×4 semiconductor optical amplifier gate switch matrix, experimentally as well as theoretically. For a fully loaded switch with the same wavelength on all four inputs, all possible switching combinations are analyzed, thus yielding realistic crosstalk figures. Coherent and incoherent crosstalk phenomena are identified, and a switch crosstalk less than -40 dB has been measured     

4×4 digital optical matrix switch using polymeric oversizedrib waveguides

For the first time the concept of oversized rib waveguides has been employed in a complex integrated optical device. Using commercially available polymers, a strictly nonblocking 4×4 digital optical matrix switch with full functionality has been realized. The matrix consists of 24 1×2 switching elements and showed a polarization independent average crosstalk of -28.8 dB     

Integrated optics 4*4 switch matrix with digital optical switches

Reports on the first 4*4 switch matrix with digital optical switches as switch elements. The matrix is arranged in a tree structure, and comprises 24 switch elements and is pigtailed and packaged.<>     

Extremely low loss 4*4 GaAs/AlGaAs optical matrix switch

A 4*4 GaAs/AlGaAs optical matrix switch with an extremely low loss of 1.6 dB has been developed. This low loss switch was achieved by layer structure modification, to reduce free-carrier absorption, reduction of plasma damage while dry etching, and an improvement in the crystal quality.<>     

Performance of 4*4 optical crossbar switch utilising acousto-optic deflector

A multicasting photonic space switch reconfigurable in 50 ns is demonstrated utilising commercially available acousto-optic Bragg cells at lambda =0.83 mu m. Insertion loss of 15 dB, extinction ratio of 33 dB, crosstalk of -24 dB and polarisation difference of 0.8 dB are reported.<>     

Hybrid-integrated 4×4 optical gate matrix switch usingsilica-based optical waveguides and LD array chips

The fabrication and characteristics of a hybrid-integrated optical gate matrix switch were studied. The switch was composed of a silica-based single-mode guided-wave circuit and two InGaAsP gate array chips, each of which comprised eight laser diode optical gates. The gate array chips were assembled on the guided-wave circuit using a hybrid integration technique. The insertion loss of the fabricated 4×4 matrix switch was scattered among switching paths and ranged from 26 to 33 dB. The switch was applicable to a 400 Mb/s signal system with a bit error rate of 10^-9. The numerical analysis shows that the residual reflectivity at the LD gate and waveguide facets caused the loss scattering among the paths and that reduction of the residual reflectivity is essential for improving the switch characteristics     

First digital optical switch based on InP/GaInAsP double heterostructure waveguides

A Y-junction digital optical switch based on InP/GaInAsP has been realised and operated using either carrier injection or carrier depletion. the switch functions with both TE and TM polarised light. In the case of current injection, 30 mA is enough to obtain a crosstalk up to 20 dB for TM polarisation and 10 dB for TE polarisation.<>     

Integrated folding 4/spl times/4 optical matrix switch with total internal reflection mirrors on SOI by anisotropic chemical etching

A folding rearrangeable nonblocking 4/spl times/4 optical matrix switch was designed and fabricated on silicon-on-insulator wafer. To compress chip size, switch elements (SEs) were interconnected by total internal reflection (TIR) mirrors instead of conventional S-bends. For obtaining smooth interfaces, potassium hydroxide anisotropic chemical etching of silicon was utilized to make the matrix switch for the first time. The device has a compact size of 20/spl times/1.6 mm/sup 2/ and a fast response of 7.5 /spl mu/s. The power consumption of each 2/spl times/2 SE and the average excess loss per mirror were 145 mW and -1.1 dB, respectively. Low path dependence of /spl plusmn/0.7 dB in total excess loss was obtained because of the symmetry of propagation paths in this novel matrix switch.     

Ti:LiNbO/sub 3/ digital optical switch matrices

Optical switch matrices were implemented using low drive voltage digital optical switches as switching elements. A drive voltage of 25 V for polarisation independent operation was achieved in a 4*4 switch. An 8*8 switch with low drive voltage could be achieved by assigning the proper lengths for switching elements.<>     

SOI热光4×4光开关阵列的研制

设计和制作了由5个2×2多模干涉马赫-曾德开关元组成的重排无阻塞型SOI 4×4热光开关阵列.阵列的最小和最大附加损耗分别为6.6和10.4dB,阵列的串扰为-12 ～-19.8dB,光开关阵列的开关速度小于30μs,单个开关元的功耗大约为330mW.     

Low-loss 4 × 4 optical matrix switch for fibre-optic communication

A low-loss and high-repeatability 4 × 4 optical matrix switch fabricated by using rhombic glass-block switch elements is described. The maximum loss was 1.3 dB and the crosstalk was less than ?55 dB, with a switching delay of less than 18 ms.     

Rearrangeable multichannel free-space optical switch using polarisation multiplexing technique

A rearrangeable free-space optical multichannel switch using the polarisation multiplexing technique is examined. The switch consists of LCTV polarisation switches and routing elements. It is shown that the switch is suitable for network reconfiguration in parallel processing systems. A 32-channel prototype optical switch was constructed, and excellent switching performance and stable insertion loss were confirmed.<>     

Tree-structured polarisation independent 4×4 switch matrix inLiNbO3

Reports on the performance of a 4×4 polarisation-independent LiNbO₃ switch matrix with a `tree-structure', permitting strictly nonblocking communicative as well as distributive switching     

4×4 GaAs/AlGaAs optical matrix switches with uniform devicecharacteristics using alternating Δβ electrooptic guided-wavedirectional couplers

Integrated 4×4 GaAs/AlGaAs optical matrix switches constructed from 12 electrooptic directional couplers have been realized. In order to achieve uniform device characteristics, molecular beam epitaxy and reactive ion beam etching were chosen as the crystal growth technique and waveguide fabrication technique, respectively, in addition to the simplified tree structure as a matrix switch architecture. As a result, matrix switches with quite uniform device characteristics, such as small switching voltage deviation and little path dependence in ±0.5-dB propagation loss, have been realized     

A high-speed 4×4 Ti:LiNbO3 integrated optic switchat 1.5 μm

The operation of a fully packaged and pigtailed polarization dependent Ti:LiNbO₃ 4×4 integrated optic switch with an operating wavelength of 1.5 μm is demonstrated. The switching matrix is fast, with a measured 3-dB small-signal bandwidth greater than 1 GHz. Unwanted cross modulation between channels due to coupling between switching elements was measured and found to be less than -20 dB of the signal strength. The switch is composed of balanced bridge switching elements having a 17-V switching voltage, an 18 dB extinction ratio, and an excess optical loss of 0.6 dB     

An 8 mm length nonblocking 4×4 optical switch array

A novel single-mode-single-slip-structure S³ optical switch using carrier-induced refractive index change is proposed as a unit cell for a small polarization-independent nonblocking N×N optical switch array. Sixteen S³ optical switches have been integrated into a nonblocking 4×4 optical switch array on an InP substrate. The 8-mm-length InGaAsP/InP 4×4 optical array has shown satisfactory switching characteristics and is suitable for larger scale integration of optical switch arrays and also for integration with other active optical devices such as laser diodes     

First demonstration of simultaneous demultiplexing from 40 Gbit/sinto two channels of 20 Gbit/s by SOA-based all-optical polarisationswitch

Simultaneous demultiplexing from 40 Gbit/s data signal into two channels of 20 Gbit/s using semiconductor optical amplifier (SOA) based all-optical polarisation switch has been demonstrated. Error-free operation was confirmed with no power penalty. This is the first experimental demonstration to prove the full-switching capability of the SOA-based Mach-Zehnder interferometer (MZI) all-optical switch at such a high bit rate regime