Freezing Optically Clear Microdroplets in a Laboratory Setting

Despite its importance in environmental, biological, geological, and extraterrestrial fields of study, ice is still poorly understood. Ice is underutilized as an optical material partly due to the disclarities often found in ice. This paper presents a method of creating frozen microdroplets for use as optical devices, especially optical resonators. We use a 3-D printed device to shape water droplets into approximate spheres. Subzero temperatures are applied to one side of the droplet in a humidity-controlled environment to freeze the droplet while maintaining its clarity. We were able to freeze clear droplets and prevent sublimation or deposition by controlling humidity.