Complex optical interference filters with stress compensation for space applications

High-performance thin-film optical filters with stress compensation

“…(3) K S is a constant term that depends on the mechanical properties of the substrate. Stress compensation was achieved using dual side coating with similar approach as for the one presented in [9]. For this, we designed structures that allow securing the same stress-induced deformation on each face, i.e.…”

“…While such deformation is not a major problem for transmitting elements, this becomes a major issue when working with reflected wavefront or with complex optical systems. In order to overcome these limitations, it is either possible to work on the mitigation of individual layer stress level [4,5], the mitigation of stress-induced deformation [6,7] or to perform stress compensation using dual side coatings with different optical functions [8][9][10]. Using the last approach, these coatings may even be designed to be athermal, i.e.…”

Polymer multimode waveguide bend based on a multilayered Eaton lens

“…Multilayered structures based on their interference effects have many applications such as antireflection coatings, Bragg mirrors, and filters [21][22][23][24]. In these structures, the thickness of the layers, d, is comparable to the wavelength of the light, λ.…”

Mechanical stress in dielectric mirrors: towards a fine control of the flatness

“…As we plotted, in Fig.2, the term K S /R Norm as a function of film thickness for both SiO 2 and Nb 2 O 5 layers, we could perform two different fits on the experimental data. In a first time, we could consider a linear evolution of the data that means a constant value of the mechanical stress as a function of the film thickness: σ i = K i [8] (i stands for either SiO 2 or Nb 2 O 5 ). In a second time we used a second order polynomial to fit the experimental data, we obtained a slightly better fit with a thickness dependence (expressed in nanometers) of the stress:…”