650+/-20nm Narrow Bandpass Filter, or said 650nm Laser Scanner Filter, is a new developed spectrum with higher transmission at T>95% @ 650+/-5nm area, perfectly used for laser equipments, such as laser scanners. The noise signals have been deeply blocked, with Tave<0.2% @ other visible light area.  

650+/-25nm bandpass filter, based on the common applications, is usually called Laser Scanner Filter, which is commonly used with from 639nm to 660nm laser light sources. It only transmit the small bandwidth of red laser light in the range of 650+/-25nm while block or reflect all the other spectrums. The blocking rate is not very strict for these types of application, because most laser scanner application just mainly required the T>90% @ centre wavelength point, without considering the noise in image forming system.. This type of filter is usually used for laser semiconductor use, such as laser bar code scanner, laser measuring equipment, 647nm laser light source device, NIR range finder, fingerprint identification system etc.