Aam Els Kok

Reduction of Propagation Loss in Pillar-Based Photonic Crystal Waveguides

Out-of-plane losses are the major issue in the integration of two-dimensional photonic crystal devices in photonic integrated circuits. In this paper, we show that the out-of-plane losses of pillar-based photonic crystal waveguides can be vastly reduced, even for pillars with a low vertical index contrast, such as in InP/InGaAsP/InP technology. These low losses are obtained by creating confinement between the pillars with a polymer layer stack. We show that the spatial frequency component of the Bloch mode in the first Brillouin zone (i.e., the component inside the light cone), is significantly suppressed by the optimized polymer layer stack.

Transmission of pillar-based photonic crystal waveguides in InP technology

Waveguides based on line defects in pillar photonic crystals have been fabricated in InP∕InGaAsP∕InP technology. Transmission measurements of different line defects are reported. The results can be explained by comparison with two-dimensional band diagram simulations. The losses increase substantially at mode crossings and in the slow light regime. The agreement with the band diagrams implies a good control on the dimensions of the fabricated features, which is an important step in the actual application of these devices in photonic integrated circuits.

Short Polarization Filter in Pillar-Based Photonic Crystals

The strong polarization dependence of two- dimensional photonic crystals is exploited for polarization filtering. The device with a length of 3.9 mum is integrated in a photonic integrated circuit based on InP waveguide technology. The average transmissions in the wavelength range from 1530 to 1570 nm are -8.7 dB for transverse-magnetic polarization and -26.5 dB for transverse-electric polarization.

Use of polarization in InP-based integrated optics

The development of integrated polarization manipulating devices opens the perspective on the use of polarization as a new design dimension in InP-based integrated optics. Examples will be given of how this results in additional functionalities.

Polarization manipulation in photonic integration on indium phosphide

The possibility to manipulate polarization in a Photonic Integrated Circuit (PIC) gives new design options. This will be illustrated with POLIS, an integration scheme based on polarization. Also the polarization manipulating devices will be introduced.