Roland Mestric

Extremely small polarization independent phased-array demultiplexers on InP

Compact, polarization insensitive phased-array wavelength demultiplexers are demonstrated with a deep ridge waveguide. Good agreement with the modeling is found for the birefringence and the refractive index. Zero birefringence is effectively obtained around 1.53 /spl mu/m. The guiding structure allows curvatures of 100 /spl mu/m; thus, the grating size of the 4- and 16-channel demultiplexers is reduced to 0.33/spl times/0.30 and 1.1/spl times/1.1 mm/sup 2/, with crosstalk below -16 and -14 dB respectively. These are the smallest demultiplexers reported to date.

1.31-1.55-μm phased-array demultiplexer on InP

The first demultiplexers on InP at 1.31-1.55 /spl mu/m based on low-order waveguide arrays have been fabricated and characterized. We show the calculated and measured spectral responses of two devices with 6 and 10 waveguides in the grating. The on-chip loss of the devices is 4.5 dB and the crosstalks are down to -25 dB. Thanks to their large bandwidth, the devices are polarization insensitive and no strong influence of the temperature is seen.

Design and fabrication of 1.31-1.55-/spl mu/m phased-array duplexer on InP

1.31-1.55-/spl mu/m InP duplexers based on low-order waveguide arrays have been modeled, fabricated and characterized. By introducing lateral offsets between straight and curved waveguides, polarization insensitive devices with 5-dB on-chip loss, and less than -30-dB crosstalk over 100-nm wavelength range have been obtained, showing good agreement between theory and experiment.

Lossless four-channel wavelength selector monolithically integrated on InP

A four-channel compact wavelength selector with 400-GHz channel spacing has been fabricated by monolithic integration on InP. Lossless operation has been achieved for all channels. Bit-error-rate performance at 2.5 Gbit/s and 10 Gbit/s has also been investigated.

Optimisation of butt coupling between deep-ridge and buried ridge waveguides for the realisation of monolithically integrated wavelength selectors

Butt coupling between deep ridge and buried ridge waveguides has been optimised in terms of morphology and transition tilt angles. Low reflectivities have been found for 15 to 30 degrees tilt angles, allowing the fabrication of a four channel wavelength selector. Loss-less operation has been demonstrated for each channel.