Streamlining the Testing Process of Photonic Chips

Abstract

The Shastri lab focuses on generating advanced photonic chips for signal processing and computing by combining artificial intelligence (AI) and photonics. These chips are utilized in neuromorphic silicon photonics which has various applications such as improving computational efficiency in AI and neuromorphic computing hardware. One of our advanced chips can be divided into three physical components: receiving a light signal, modulating the signal, and lastly detecting the signal with a photodetector on chip. Prior to utilizing these chips for experiments, it is vital to ensure that all components are functioning correctly.
 My work focused on streamlining the testing process of the photodetector by improving the signals used within the process. In order to test the photodetector, the light entering must be modulated externally using a Mach-Zehner Modulator (MZM). The MZM takes in a light signal and splits it into two where they experience a phase shift and when the two are recombined create a modulated signal. The signal’s modulation is determined by changing the radio frequency (RF) signal sent from a driver into the modulator.
 Another aspect of my work was enhancing the control of the RF signal produced by the driver. The driver requires specific positive and negative voltages to generate ideal frequencies which are supplied by a unique power source. The voltage source was designed to ensure that the driver never received a damaging current or voltage and had a user-friendly interface to control the modulation of the signal.