Hi John,

The glass catalogs are text files with the *.AGF extension (meaning you can open them with a text editor). Their syntax is described in the Help File under:

The Libraries Tab > Optical Materials Group > Using Material Catalogs > The AGF & BGF File Formats

You can use a third-party programing langage, such as Python, to parse through the files. I have done a dummy example for you below, which returns the glass vendors and names for each glass found in the GLASSCAT folder. Note that you need to change the path to your own GLASSCAT folder.

import os

# Path to {Documents}\Zemax\Glasscat
path = r'C:\Users\David Nguyen\Documents\Zemax\Glasscat'

# Initialize return array, which will contain the glass names and vendors
allglass = []

# Loop over the files in the GLASSCAT folder
for glasscat in os.listdir(path):
    # Select files with the *.AGF extension
    if glasscat.lower().endswith('.agf'):
        # Save vendor name
        vendor = glasscat[:-4]
        
        # Read the file
        with open(os.path.join(path, glasscat)) as glasstxt:
            # Search for the lines starting with NM (contains the glass name)
            for line in glasstxt:
                if line.lower().startswith('nm'):
                    # Save the glass name
                    glassname = line[3:]
                    glassname = glassname[:glassname.find(' ')]
                    allglass.append((vendor, glassname))
        
# Display results
for glass in allglass:
    print('Vendor: ' + glass[0] + ' | Glass: ' + glass[1])

If you run the code above, it’ll return the following (for all vendors and glasses):

Since you know the syntax of the glass catalogs, you can virtually return anything from the different glasses, and also make your own custom catalog.

I hope this helps,

David

Hi John,

I have made a second version of the code that implements the Schott formula at a single wavelength for your reference. Please note, it only returns glasses which use the Schott formula. I don’t have the time to implement all the formulas, but I believe it shouldn’t be too hard to complete.

import os

# Path to {Documents}\Zemax\Glasscat
path = r'C:\Users\David Nguyen\Documents\Zemax\Glasscat'

# Initialize return array, which will contain the glass names and vendors
allglass = []

# Dispersion formula flag
dispersionform = -1

# Wavelength of interest in micrometres
wave = 0.7

# Loop over the files in the GLASSCAT folder
for glasscat in os.listdir(path):
    # Select files with the *.AGF extension
    if glasscat.lower().endswith('.agf'):
        # Save vendor name
        vendor = glasscat[:-4]
        
        # Read the file
        with open(os.path.join(path, glasscat)) as glasstxt:
            # Search for the lines starting with NM (contains the glass name)
            for line in glasstxt:
                if line.lower().startswith('nm'):
                    # Split the parameters of the glass name entry
                    glassnamedata = line.split()
                    
                    # Save the glass name
                    glassname = glassnamedata[1]
                    
                    # Dispersion formula
                    dispersionform = int(float(glassnamedata[2]))
                else:
                    # Are we returning the refractive index?
                    if line.lower().startswith('cd') and dispersionform != -1:
                        # Schott dispersion formula
                        if dispersionform == 1:
                            dispersioncoef = line.split()
                            
                            # Coefficients
                            a0 = float(dispersioncoef[1])
                            a1 = float(dispersioncoef[2])
                            a2 = float(dispersioncoef[3])
                            a3 = float(dispersioncoef[4])
                            a4 = float(dispersioncoef[5])
                            a5 = float(dispersioncoef[6])
                            
                            # Refractive index
                            nschott = a0 + a1 * wave**2 + a2 * wave**-2 +\
                                a3 * wave**-4 + a4 * wave**-6 + a5 * wave**-8
                            nschott = nschott**0.5
                            
                            allglass.append((vendor, glassname, str(nschott)))
                            
                        # Reset flag
                        dispersionform = -1
        
# Display results
allglasstxt = ''

for glass in allglass:
    allglasstxt += 'Vendor: ' + glass[0] + ' | Glass: ' + glass[1]
    allglasstxt += ' | Refractive index (Schott): ' + glass[2] + '\n'
    
with open('allglass.txt', 'w') as glasstxt:
    glasstxt.writelines(allglasstxt)
                

This is what it looks like for the glasses that use the Schott formula and a wavelength of 0.7 um:

Take care,

David