Overview
The careful characterization of the polymer waveguides in terms of optical properties (e.g. optical losses and modal dispersion) as well as reliability (environmental stability) is one of the main tasks of a successful waveguide technology development.
The waveguide propagation losses belong to the most decisive properties. Based on our power budget considerations for a complete optical link of up to 1 m length we anticipate a propagation loss of ≥0.05 dB/cm at λ = 850 nm VCSEL wavelength. For the evaluation of appropriate low-loss polymer materials, we established a very accurate loss measurement method based on small-footprint 100-cm-long waveguide spirals.
In the course of our polymer evaluation, we found several polymer systems which can fulfill the loss expectations of 0.05 dB/cm at λ = 850 nm.
In the course of our polymer evaluation, we found several polymer systems which can fulfill the loss expectations of ≥0.05 dB/cm at λ = 850 nm.
With other waveguide test structures as bendings, crossings, splitters we determined further key data characterizing our waveguides:
- bending loss: 0.1 dB per 180° bending with 20 mm radius,
- crossing loss: 0.02 dB per perpendicular crossing,
- waveguide splitter loss: 0.1 dB per 1:1 splitter,
- modal dispersion: open eyes @ 12.5 Gb/s (measured with 100-cm-long waveguide spiral: 50 µm core).
Images
Figure 1. Waveguide reference.
Figure 2. Waveguide spiral.
Figure 3. Light propagation in spiral.
Figure 4. Polymer systems 1-4 (click on desired chart to enlarge).
Figure 5. Waveguide crossing.
Figure 6. Crossing loss.
Figure 7. Waveguide splitter and 1:1 splitting.
