Flattened response ensures polarization independence of InGaAsP/InP phased array wavelength demultiplexer

A four channel polarization independent phased-array wavelength demultiplexer has been made by using different array orders for TE and TM. The insertion loss is 3.5 dB and the crosstalk is -16 dB. TE/TM peak position difference is only 0.2 nm. The response is flattened over 0.5 of the 1 nm channel spacing, yielding 0.3 nm of polarization independent flattened response for each channe

Phased-array wavelength demultiplexer with flattened wavelength response

A four-channel phased-array wavelength demultiplexer with a flattened wavelength response has been realised for the first time in InP/InGaAsP at 1.54 mu m by employing multimode output waveguides. The device has 2 nm channel spacing and a flat response (within 1 dB) of 17 n

Low-crosstalk and low-loss waveguide crossings on InP with small dimensions

With the increasing scale of integration, resulting in a higher on-chip complexity, waveguide crossings with good performance are becoming increasingly important. Worst-case paths contain a high number of crossings, depending on the number of channels being processed, in switching matrices, multiwavelength add drop filters (up to 15), and optical cross-connects. Crossings with very low crosstalk and loss can be realized in fiber-matched waveguide structures as used in lithium niobate or silica-based technology. In highly integrated semiconductor devices, crossings may contribute significantly to the loss and crosstalk performance. In this paper we present the results of a series of experiments for the design of high-performance semiconductor waveguide crossing

Compact InP-based waveguide crossings with low crosstalk and low loss

Waveguide crossings with small intersection angles have been fabricated in a InP-based waveguide structure. Measurements yielded crosstalk values of less than -30 dB and excess loss values of less than 0.3 dB for intersection angles down to 30 degrees, for both TE and TM polarisation. It is shown that the multiple scattering interaction (MSI) correctly predicts the magic angles. A 2D-beam propagation method (BPM) gives a good quantitative fit to the experimental results. Further improvement of semiconductor waveguide crossing performance will gain importance with increasing complexity of circuit design

Phased-array wavelength demultiplexer with flattened wavelength response

A four-channel phased-array wavelength demultiplexer with a flattened wavelength response has been realised for the first time in InP/InGaAsP at 1.54 mu m by employing multimode output waveguides. The device has 2 nm channel spacing and a flat response (within 1 dB) of 17 n

Design and realization of polarization independent phased array wavelength demultiplexers using different array orders for TE and TM

A method for designing polarization independent phased-array wavelength demultiplexers, using different array orders for TE and TM, is described and analyzed with respect to fabrication variations. Flattening of the wavelength response is shown to improve fabrication tolerances. A four channel phased-array wavelength demultiplexer with at least 0.2 nm of polarization independent flattened response for each channel (spacing 1 nm) has been made with an insertion loss of 1.5-3 dB and a crosstalk of -17 to -19 d