Waveguide Optical Power Converter With Side Illumination
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Solution Overview
Problem
Conventional optical power converters face limitations in conversion efficiency and voltage output due to top illumination configurations, which result in transmission and resistive losses, shadowing of light, and increased recombination losses, especially at higher power densities.
Innovation Solution
The optical power converter employs a semiconductor waveguide structure with a side illumination configuration, featuring thin light absorbing layers and a transverse waveguide design that minimizes shadowing and resistive losses, allowing for extended optical path lengths and higher photo-carrier densities, thereby increasing open circuit voltage and conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If top illumination configuration is used with metal grid contacts, then light collection area is increased, but transmission losses and shadowing effects increase reducing conversion efficiency
Solution Approach 1:
The patent inverts the conventional top-illumination configuration by implementing side illumination where light enters through the edge of the waveguide structure rather than the top surface. This inversion eliminates the need for top metal grid contacts that cause shadowing, while the entire top surface becomes available for light collection through the waveguide's lateral faces.
Solution Approach 2:
The patent transitions from two-dimensional top surface illumination to three-dimensional edge illumination by directing light along the lateral faces of the waveguide. This dimensional change allows light to propagate through the waveguide structure in a direction parallel to the layers, utilizing the full perimeter of the device for light collection without shadowing losses.
2Loss of energy
If thin absorbing layers are used to reduce recombination losses, then voltage output increases, but light absorption efficiency decreases
Solution Approach 1:
The patent extends the optical path length by directing light laterally through the waveguide structure over an extended distance. This continuous propagation of light through the thin absorbing layer along the waveguide length ensures complete absorption of photons while maintaining the benefits of thin layers for reduced recombination and high voltage output.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances conversion efficiency and voltage output by reducing transmission and resistive losses, achieving open circuit voltages within 90% of the band-gap energy and supporting higher incident power densities without significant recombination losses.
Implementation Method 1
The device may comprise a semiconductor waveguide structure configured to confine and guide light through the device, where it can be absorbed and converted to electrical charge
Implementation Method 2
The one or more light absorbing layers may be thin, having a total thickness (in the growth direction) of substantially less than 100 nm... Photo-carriers (photo-generated electrons and holes) are generated in the light absorbing layer(s) through absorption of photons in the light beam
Data Source
AI summary
An optical power converter device (200, 300) comprises a semiconductor waveguide structure having a first end facet (F1) configured to receive an incident light beam, and one or more light absorbing layers (210a) with a total thickness of substantially less than 100 nm and configured to absorb light guided by the waveguide structure. The device further comprises a cathode (202) and an anode (204) in contact with substantially the entire length of the waveguide structure in the direction of propagation of light from the first end facet for outputting generated electrical power. An optical power converting system (1000) comprising the optical power converter device is also provided, as is a method of operating the optical power converter.