• SCHOTT Introduces New Blue Glass Filters that Feature Superior Heat and Humidity Resistance
BG60 and BG61 both offer a climatic resistance that is much higher than the current SCHOTT BG series. BG61 has a higher passband that simplifies an additional interference coating.
January 24, 2012 (San Francisco, CA) – At Photonics West 2012, SCHOTT Advanced Optics, the international technology group with one of the world’s largest Optical glass portfolios, will be introducing two new filter glass types: BG60 and BG61. Offering outstanding climatic resistance (i.e. to heat and humidity), these Blue Glass (BG) filters are suited to cut the infrared from the visible light, e.g. in digital camera applications.
Image sensors have become commonplace. Integrated into cell phones and laptops, digital compact cameras and single lens reflex cameras as well as line scan camera systems and range finders, their CCD and CMOS sensors are often equipped with infrared (IR) cut filters in order to get natural colors. They make digital cameras respond to light as our eyes do.
However, many IR filters are made of filter glass containing phosphate that can come into contact with condensation especially in warm and humid areas e.g. a production hall or a balmy summer day. The filter’s surface occasionally begins to corrode and turns matte, which, in turn, lowers its desired transparency for visible light.
SCHOTT’s new IR filter glasses BG60 and BG61 have been designed to perform in difficult environments. Tested at the industry’s most demanding specifications of 85° Celsius and 85 percent relative humidity, their surfaces stay corrosion-free for hundreds of hours. Equipped with an additional coating, they remain completely transparent for more than 1000 hours without any surface corrosion.
The glass is melted in a continuous process that allows for outstanding reproducibility with consistent transmission and wavelength characteristics. Thanks to the optimized composition and processing, the new BG filter glasses have an outstanding bending strength that guarantees for excellent machinability and allows for employment in heavy duty applications.
BG filters can be used in a wide range of applications including medical, imaging, surveillance and industrial applications such as airport lighting and laser safety applications. At 0.3 mm thickness, BG60 offers a 50 per cent transmission (T50) around 633 nm, B61 has its T50 at around 644 nm. BG60 and BG61 both offer a much higher climatic resistance than the current SCHOTT BG series. BG61 has a higher passband that simplifies an additional interference coating.
Besides the new BG glasses, SCHOTT will be exhibiting its extensive range of optical filter glasses for wavelengths of 250 nm to 1200 nm at Photonics West to meet any specific customer requirements. Manufactured, polished, and supplied in different thicknesses they can be delivered with an anti reflective (AR) or an additional interference coating to enhance the optical filter.
SCHOTT’s portfolio covers bandpass filters, that selectively transmit a desired wavelength range, longpass filters, that transmit a desired longer wavelength range, shortpass filters, that transmit a desired shorter wavelength range, and neutral density filters, that exhibit nearly constant transmission, especially in the visible range. By combining different filters, additional filter effects can be achieved.