BK7 Plano concave lens(PCV) is mainly used in diverging parallel light. BK7 material has high transmittance from visible light to near infrared(350-2000nm). When don’t need the feature of uv silica material, often use this type in laser and telescope application.
UV fused silica material plano concave (PCV) has high transmittance in ultraviolet to infrared wavelength(185-2100nm) especially in deep ultraviolet region. This type plano concave lens is widely used in high power laser and imaging system.