一下内容摘自：
https://my.zemax.com/en-US/Knowledge-Base/kb-article/?ka=KA-01668
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Coating specifications
To model the dichroic coating, we will use a table coating in OpticStudio. Of the different coating formats available in OpticStudio, table coatings are among the most flexible. Table coatings allow the transmission, reflection, and absorption properties of a coating to be wavelength, polarization, and angle of incidence dependent. Phase rotations can also be modeled by table coatings. All of this can be done without knowing the specific material properties of the coating being modeled. This is useful because many coating vendors are unwilling to provide specific coating prescriptions. They are usually more willing, however, to provide coating performance information (i.e. relative transmission/reflection data at various wavelengths/angles of incidence).
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The table coating format in OpticStudio is compatible with the output from The Essential Macleod thin film software (
www.thinfilmcenter.com).
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For table coatings, data is normally specified at multiple angles of incidence. At each angle of incidence specified, the polarization dependent reflection and transmission for several wavelengths is specified. The syntax for table coatings is as follows:
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TABLE [coating name]
ANGL [angle of incidence 1, in degrees]
WAVE [wavelength 1, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
WAVE [wavelength 2, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
WAVE [wavelength 3, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
...
ANGL [angle of incidence 2, in degrees]
WAVE [wavelength 1, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
WAVE [wavelength 2, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
WAVE [wavelength 3, in mm] [Rs] [Rp] [Ts] [Tp] [Ars] [Arp] [Ats] [Atp]
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where:
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Rs = Reflection coefficient for S polarization
Rp = Reflection coefficient for P polarization
Ts = Transmission coefficient for S polarization
Tp = Transmission coefficient for P polarization
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The remaining parameters are the phase rotation angles. These are optional and, in our case, can be left off. If the angles are omitted, no phase change will be introduced by the coating.
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Since the reflection and transmission coefficients can be defined separately for S and P polarization states, table coatings can be used to model polarizing beam splitters in OpticStudio.
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Given the geometry of our system, we are only interested in one angle of incidence (45 degrees) and two wavelengths (0.400 and 0.525 mm). As stated previously, we are going to assume that our dichroic coating is polarization insensitive (for simplicity). As such, the amount of reflection will be the same for S and P polarization orientations (as will the amount of transmission). Since the 0.40 micron wavelength is in the pass band, the transmission at this wavelength should be 100% and the reflection should be 0%. Likewise, since the 0.525 micron wavelength is in the stop band, the transmission at this wavelength should be 0% and the reflection should be 100%. As such, the resulting table coating is:
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TABLE SWP
ANGL 45
WAVE 0.400 0.0 .0.0 1.0 1.0
WAVE 0.525 1.0 1.0 0.0 0.0
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Using a text editor (such as Notepad or EditPlus2), open a blank text file and enter the text above.
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We will also need to setup our ideal AR coating. Recall that the AR coating we are going to model in this case is one which reflects 1% and transmits 99%. Since we are not modeling any absorption, wavelength or angle of incidence dependence for this coating, we can use the simple "I.transmission" ideal coating format:
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COAT I.99
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Add this coating to your file as well.
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Once you have defined the two coatings, save your coating file using an appropriate filename (such as DICHROIC.DAT) in the appropriate directory. Remember that the coating file must end in the extension .DAT and must be stored in the same directory as your other coating files (the default is {Zemax}/Coatings).
发表于 2021-7-8 13:11
