1.  Home
  2. Whitepapers
  3. Optical Filter Surface Quality

Optical Filter Surface Quality

Download Whitepaper

Optical Filter Surface Quality

Download Whitepaper
Surface quality and internal element quality are specifications which are used to define the level of defects to be allowed on the surface of an optical filter or within the element. Methods for specifying and inspecting surface quality have been defined by the U.S. Army in three commonly used military specifications; MIL-O-13830, developed in 1954 and revised to it's current level in 1963, MIL-C-48497, developed in 1974 and revised to it's current level in 1980, and MIL-F-48616, developed in 1977. These specifications categorize surface defects as either scratches or digs which can be defined as follows: Scratch - A surface defect(tear) having length well in excess of width. Dig - A surface defect(hole) having length approximately equal to width or being approximately circular in shape.Scratches and digs are quantified by width and diameter, respectively, to allow for a universal specification language. In the newer military specifications, scratches are specified in units of 0.001mm, and digs, in units of 0.01mm. The commonly used scratch and dig sizes have been assigned letter designations. The tables that follow, set forth the commonly used specification values.

Download Whitepaper Now