Fuzhou Siaon Optoelectronic Technology Co., Ltd.provides Glan Thompson Polarizers Glan Thompson Polarizer is made of two calcite prisms or two a-BBO prisms cemented together. Two types of Glan Thompsons are available. Glan Thompson polarizers tend to have higher extinction ratio than air spaced polarizers. a-BBO polarizers and Calcite polarizers can be used from about 220 to 900nm and 350 to 2300nm respectively.