Every three years the OSA (Optical Society of America) holds a meeting called OIC (Optical Interference Coatings). As part of that meeting, there is always a design contest. The 2007 meeting has two design problems, the second of which is discussed here. The first problem is a Triple Bandpass Filter.
The challenge is to design a 45° beamsplitter on a glass (index 1.52) substrate. The incident and exit mediums are air. Only the front side of the substrate needs a coating; we can assume the back side has a perfect AR coating. For a wavelength range as wide as possible, and centered at 550 nm, the beamsplitter design has the following performance requirements:
| Rs - Rp | ≤ 2%
40% ≤ Rs ≤ 60%
40% ≤ Rp ≤ 60%
| δRs - δRp | ≤ 1° (difference of p and s reflected phase, Abeles convention)
| δTs - δTp | ≤ 1° (difference of p and s transmitted phase) The coating design may use a maximum of three materials from the following list of seven indices: 1.38, 1.45, 1.65, 1.8, 2.05, 2.2, and 2.35. The materials are assumed to be dielectric and non-dispersive. There is no limit on the number of layers. However, layers are required to be at least 5 nm thick. The design is to be evaluated every 0.001 nm to ensure that all requirements are met. The winning design is the one that meets the requirements for the widest wavelength range centered at 550 nm.
Nonpolarizing Beamsplitter for OIC Contest
Every three years the OSA (Optical Society of America) holds a meeting called OIC (Optical Interference Coatings). As part of that meeting, there is always a design contest. The 2007 meeting has t...