Design of a new ultra-small polarization converter in InGaAsP/InP membrane

The design of an ultra-small (4.1 µm length) polarization converter in Indium phosphide (InP) membrane is presented. The device is modelled using a vectorial 2D mode solver. Simulations show strong conversion (> 94%) and low-loss operation (<0.5 dB) over a wavelength range of 200 nm. A description of a possible fabrication scheme for the device using standard InP technology is also given

Oxidation of AlInAs for current blocking in a photonic crystal laser

To make an electrically pumped photonic crystal membrane laser is a challenging task. One of the problems is how to avoid short circuiting between the p- and n-doped parts of the laser diode, when the membrane thickness is limited to 200-300nm. We propose to use the oxide of AlInAs to realize a current blocking function. In this way, based on submicron selective area re-growth, we aim for electrically injected photonic crystal lasers with high output power, small threshold currents and low power consumption. Here results are presented on the oxidation of AlInAs. The results show that it is feasible to use the oxide of AlInAs for current blocking in an InP-based membrane photonic crystal laser

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 d

BCB bonding of high topology 3 inch InP and BiCMOS wafers for integrated optical transceivers

In this publication the challenges of bonding InP and BiCMOS wafers with high topology are described. A possible process is discussed. Planarization with thick BCB is motivated and the challenges of wafer alignment are explained

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

A compact integrated polarization splitter/converter in InGaAsP/InP

A novel design for an integrated passive polarization splitter/converter combination is presented. The device consists of a Mach-Zehnder interferometer with polarization converters in both arms. The device is analyzed using the transfer matrix method and fabricated in InGaAsP-InP. Measurement results show a splitting ratio of approximately 10 dB and a conversion of >90%. This device can be monolithically integrated with passive and active components

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

\u3cp\u3eA 4-channel phased-array wavelength division demultiplexer with 1.8 nm channel spacing at 1.54μm 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 -12 to -21 dB.\u3c/p\u3

4-Channel wavelength flattened demultiplexer integrated with photodetectors

We report the first 4-channel wavelength demultiplexer with flattened response, monolithically integrated with photodetectors. The demultiplexer is realized in InP-InGaAsP and operates around a centre wavelength of 1533 nm with a wavelength spacing of 2.0 nm. The response is flat within 1 dB for a 1.2 nm band centered around the transmission wavelength. Crosstalk remains below -20 dB. On-chip losses are estimated at -6.0 dB. Photodetector capacitances and dark currents at -5 V bias are 0.5 pF and better than 8 nA respectivel

A single etch-step fabrication-tolerant polarization splitter

A tolerant single etch-step passive polarization splitter on InP/InGaAsP is designed and fabricated. The device consists of a directional coupler with a wide and a narrow waveguide. Modal birefringence of the third-order modes for transverse electric (TE) and transverse magnetic (TM) polarizations is employed to selectively couple one polarization. Tapering is applied to increase the tolerances. The devices are characterized, and the measurement results show good agreement with the beam-propagation-method simulations: a splitting ratio larger than 95% for a width range of around 100 nm and over a large wavelength range, covering at least the C-ban