J.J.G.M. van der Tol

Low-loss phased-array based 4-channel wavelength demultiplexer integrated with photodetectors

A 4-channel phased-array wavelength division demultiplexer with 1.8 nm channel spacing at 1.54 /spl mu/m has been monolithically integrated with photodetectors in InP/InGaAsP. On chip losses are 3.5 to 4.5 dB. These are the lowest losses reported so far for demultiplexers monolithically integrated with photodetectors. Nearest neighbor crosstalk ranges from /spl minus/12 to /spl minus/21 dB.<<ETX>>

A new short and low-loss passive polarization converter on InP

We propose an improved polarization converter in InGaAsP-InP. It contains a series of waveguide sections with asymmetric cross-sections with angled facets. A 09-mm-long TE/TM-converter at a wavelength of 1.5 /spl mu/m is simulated. It contains 10 sections and has an excess loss of 0.25 dB. Both coupled mode theory and beam propagation method (BPM) simulations are included.<<ETX>>

A low-loss 16-channel polarization dispersion-compensated PHASAR demultiplexer

An improved technology for realizing high-quality PHASARs is reported, which is compatible with the integration of electrooptical switches for use in add-drop multiplexers. This technology is demonstrated in a 16-channel polarization independent low loss (<2.4 dB on-chip) PHASAR.

A short polarization splitter without metal overlays on InGaAsP-InP

A new and very short polarization splitter on InGaAsP-InP is designed and realized for the first time. The component contains a ridge waveguide directional coupler of 0.4 mm length and an output section of 0.7 mm. It uses the large waveguide birefringence of the first-order TE and TM modes to obtain polarization selective directional coupling. In this way, additional metal layers on the waveguides to create birefringence are avoided and fabrication becomes very simple. Components are realized, which show splitting ratios close to -20 dB. Excess losses are below 1 dB. The polarization splitting is investigated in the wavelength region of 1525-1560 nm and found to be better than -9 dB.

Mode evolution type polarization splitter on InGaAsP/InP

A new type of mode-evolution polarization-splitter based on InGaAsP/lnP has been designed and realized. The component uses the large waveguide birefringence of the first-order TE and TM modes in a ridge waveguide made in a heterostructure, In the input section an asymmetric Y-junction acts as a mode converter in order to inject first-order TE- and TM-modes in a polarization-splitting section, which consists of a Y-junction formed by a bimodal and a monomodal waveguide. In the output section a third Y-junction is connected to the bimodal waveguide to couple the first-order mode to a monomodal output waveguide. Components that are 6-mm long and show polarization splitting at a wavelength of 1.55 mu m have been realized. The best splitting ratios are close to -20 dB, which is in agreement with BPM simulations. Excess losses are below 1 dB.<<ETX>>

Realization of a short integrated optic passive polarization converter

For the first time, passive polarization converters with lengths of less than 1 mm and high polarization conversions are realized on InGaAsP-InP. Angled facets in a periodic coupler are used to obtain efficient conversion. Polarization conversions of more than 70%, respectively more than 90%, are measured for two different realizations of the angled facets. The most promising technology used in the realization results in a propagation loss of less than 1 dB/mm for both polarizations.<<ETX>>

A Mach-Zehnder-interferometer-based low-loss combiner

Passive optical combiners have an unwanted 3-dB loss. This is avoided with optical switches, but these need control functions to synchronize with the optical signals. A nonlinear Mach-Zehnder interferometer can provide the combiner function without control signals. In the experiment reported here, this combiner was realized with a fiber component. Semiconductor optical amplifiers (SOAs) acted as the nonlinear phase shifting elements. Thus a proof-of-principle for the self-routing combiner is obtained: optical signals on either of the two input ports are guided to one and the same output port without any control mechanism in the interferometer. The nonlinear effect used is self-phase modulation, caused by carrier depletion in the SOAs as they approach saturation. The optical power at which the nonlinear switching occurred was about -2 dBm. The residual combiner loss was only 0.7 dB.

InP photonic circuits using generic integration [Invited]

InP integrated photonics has become a critical enabler for modern telecommunications, and is poised to revolutionize data communications, precision metrology, spectrometry, and imaging. The possibility to integrate high-performance amplifiers, lasers, modulators, and detectors in combination with interferometers within one chip is enabling game-changing performance advances, energy savings, and cost reductions. Generic integration accelerates progress through the separation of applications from a common technology development. In this paper, we review the current status in InP integrated photonics and the efforts to integrate the next generation of high-performance functionality on a common substrate using the generic methodology.

Integrated Parallel Spectral OCDMA En/Decoder

In this letter, a passive integrated device is presented that enables cost-effective parallel encoding and decoding in a spectral amplitude encoded optical code-division multiple-access transmission system. The device is monolithically integrated in InP-InGaAsP. Simulation and experimental results are given

Current Status and Prospects of Photonic IC Technology

The most complex photonic ICs today have been developed for WDM applications. An overview of the most important integration technologies will be given and recent developments towards broader applications and higher integration densities will be discussed.