Philip Baumeister

Antireflection coatings for germanium IR optics: a comparison of numerical design methods

Refinement and thin film synthesis methods were used by members of six different institutions to design antireflection coatings for germanium substrates. The solutions are based on the use of zinc sulfide and germanium layers only. Several systems were found with an average reflectance that is less than 1% in the 7.7 to 12.3 microm spectral region.

Bandpass design–applications to nonnormal incidence

A five-cavity bandpass is designed. The spectral transmittance simulates a Chebyshev polynomial. The same principles are used to design a bandpass that resides in a cemented cube at a 45 degrees angle of incidence that has minimal polarization splitting.

Multilayer reflectors with suppressed higher-order reflectance peaks

Dielectric multilayers that have substantial reflectance at relatively long wavelengths and high transmittance at shorter wavelengths are designed.

Antireflection coatings with Chebyshev or Butterworth response: design

Approximations are developed for the refractive indices of nonabsorbing layers with equal optical thickness producing an antireflection coating for a dielectric substrate that has a Chebyshev spectral response.

Prediction of the bandwidth of an all-dielectric bandpass filter

The bandwidth between adjacent stop bands is useful in the design of a multilayer all-dielectric bandpass with a prescribed bandwidth.

Spectral characteristics of a narrowband rejection filter

A krypton ion laser was used to measure the spectral characteristics of a narrowband multilayer dielectric rejection filter produced by plasma chemical vapor deposition.

How an optical coating alters the path of a ray

In numerous instances a ray propagating through an optical system penetrates a multilayer coating such a bandpass filter, polarizer, beamdivider or antireflection coating. The additional retardance that the coating adds to that ray is, to a first approximation, the optical thickness of the multilayer. Several examples are given.