Laser Scanning Microscope for Van der Waals Material Studies

Laser-scanning optical microscopy techniques have come into widespread use in recent years in fields ranging from cell biology to semiconductor physics as a result of their ability to facilitate rapid acquisition of spectrally resolved images. However, commercially available devices can be expensive, and they may not provide the flexibility necessary for customized applications in materials science. Here, we report on a custom-built system circumventing these cost and flexibility issues for an application aimed at measuring the temperature-dependent spectroscopic properties of van der Waals-bonded materials. We incorporated Arduino-controlled Picomotor actuators and developed a software-based user interface for refined mirror adjustments and precise light guidance. The guidance system was directed into an optical cryostat capable of varying the temperatures of materials samples as low as 3.5 K. The setup enables detailed analyses of samples like an MoS2 exfoliated monolayer on SiO2/Si and 20-nm-thick GaAs quantum wells. In broader context, it is expected to offer insights into material efficiencies and applications in a variety of industrial contexts like low-power electronics and quantum devices.