Fully transparent GaN/InGaN LED as a position sensitive detector

Commercial optical technologies have an increasing need for an accurate, in-situ beam locator to ensure laser alignment during operation. In this work, gallium nitride LEDs with indium gallium nitride quantum wells are leveraged to create a fully transparent two-dimensional position sensitive detector (PSD). Two different architectures are developed and characterized. Fabricated devices are shown to successfully and repeatably locate 405 nm laser light in two dimensions in the PSD area with a limit of detection of 8.4 μm while maintaining approximately 3% linearity.