Let It Snow!

lynn.savage@photonics.com

Crystals show up everywhere in the photonics world and are vitally important to the laser and optics fields in particular. But crystalline silica, sapphire and other materials are not as fragile and transitory as water ice crystals: snow.

People become fans of snow at a young age – if they live in the right regions to be exposed to it. They may even remain fans after they grow up and have to shovel copious amounts of it and drive through it. Some people enjoy snow so much that the startling intricacies of ice crystal formation drive them to become scientists. One scientist who has carried his passion for snow crystals into his academic career is Kenneth G. Libbrecht of California Institute of Technology in Pasadena.

Photos courtesy of Kenneth G. Libbrecht, California Institute of Technology.

Using a custom-made photomicrography system, Libbrecht has traveled the world taking amazing still shots of individual crystals and even videos showing how the crystals form. Shown on this page are some of his photos illuminating the various forms that snow crystals can assume. Libbrecht also hosts a website, snowcrystals.com, that features an excellent guide to snow crystals and flakes, including a primer on snow formation and instructions for building and using a personal snow photomicroscope.

The hobby is not for anyone intimidated by the cold, however; according to Libbrecht, he gets the best results when the temperature is about —15 °C, or 5 °F.