Software for calculation diffraction gratings efficiency

PC GRATE

What for it was created?

The effective use of diffraction gratings in optical systems requires an understanding of how grating parameters affect a system’s range and performance. Accurate knowledge of the diffracted efficiency over the entire wavelength (or other parameter) range is essential for both accurate performance analysis and for optimizing the design of many grating based applications. PC Grate software enables the user to solve rigorously the electromagnetic periodic boundary value problems corresponding to a beam of light incident on a plane diffraction grating. The use of PC Grate series software can assist in both system analysis and system design. To illustrate the former, a chosen grating’s parameters such as groove profile and spacing can be entered. The complete efficiency performance would then be characterized over the entire useable wavelength range for that system’s geometric configuration. As an example of the latter case, a grating system in the design stage can be modeled by scanning variations of appropriate parameters such as angle, depth, and profile type. Once optimized, the results could be used to select a standard available grating, or become the basis of a custom design. The relevant part of the system layout can be incorporated directly in this efficiency performance analysis. Manufacturers of grating structures would also realize dramatic benefits from reduction in the intensive test and measurement time required by the grating fabrication process. The efficiency data computed by PC Grate has been tested by comparisons with experimental data and published calculated results.

Refractive Indices Libraries

It is possible to set grating surface material by linking of Refractive Indices Library (RIL). Using a RIL permits the scanning of wavelength, incorporating a change in index for each wavelength value.
A linking of a RIL-file means that the program will search the R.Index for the current wavelength in an active (linked) library file. If the library does not contain the exact value of wavelength, the linear interpolation and extrapolation are performed.
It is impossible to set permittivity mode (squared refractive index) with a connected RIL.

Spectral Region

PC Grate-1E, 2X, 3E: from UV to far IR and microwave.
PC Grate-4E: from UV to X-ray.

Orders

PC Grate-1E, 2X, 3E: -150 till +150.
PC Grate-3E, 4E: -5 till +5.

Gratings profiles

PC Grate can determine the diffraction efficiency for a wide class of profiles, including triangles and trapezoids formed by straight line segments, as well as trapezoids whose slopes are sine shaped segments. Cases of particular interest are laminar (or lamellar) gratings made by photolithography and sinusoidal profiles generated by holographic exposure in photo resist.
Besides that, PC Grates can process cylindrical, abs(sin), asymmetrical profiles and USER DEFINED (manually entered) profiles.

Download

Download DEMO of PC Grate-1E, PC Grate-2X, PC Grate-3E, PC Grate-4E.

Comments

PC Grate-1E assumes infinite conductivity of the grating substrate.
PC Grate-2X works assuming finite conductivity of the grating substrate.
PC Grate-3E solves transmission diffraction gratings assuming no absorption of the grating substrate.
PC Grate-4E works in UV and X-ray ranges.

NEW! PC-Grate for WDM & DWDM Applications
The new PC Grate-2X version has ability to calculate diffraction gratings for WDM & DWDM systems. It calculates the profile of choosen type of grating according to the required efficiency, angle of incidence in a specified wavelength region. The calculations are carrying in a way to provide minimum polarization difference.