Specifying Optical Filters
The first step toward developing a successful design of any optical filter is having an understanding of the operating environment of the filter. Parameters such as angle-of-incidence, operating temperature, illumination source, and detector have a significant effect upon filter performance. The following is a description of all the important parameters associated with the specifications of Optical Filters:
Application
- Description of Application
- Instrument Requirements
- Fluorophores (where applicable)
Spectral Requirements
- Transmission requirement and region of interest
- Reflection requirement and region of interest
- OD Blocking requirement
- Edge steepness
- Edge placement
Optical Requirements
- Surface Quality
- Flatness (S1)
- Flatness (S2)
- Parallelism
- Transmitted Wavefront
Operating Conditions
- Operating Temperature
- Storage Temperature
- Humidity
Optical System
- Angle of Incidence
- Cone Half Angle
- System Speed
- Illumination Source
- Detector
- Polarization State
Substrate Requirements
- Length and Tolerance
- Width and Tolerance
- Diameter and Tolerance
- Thickness and Tolerance
- Clear Aperture
- Edge Treatments
- Bevel
- Edge Blackening
- Filter Housing
Durability Requirements
- Hardness
- Adhesion
- Humidity
Other Requirements
- Part identification and marking/li>
- Part Orientation
- Packaging requirements
- Packaging label requirements
- Data correlation / Lot traceability