Diffraction Grating Part Number System

All standard Richardson gratings have a catalog number, according to the following format:


Diffraction Grating Type (AA)

The 1st and 2nd characters AA are numerals that indicate the type of grating:

Grating Type Code AA Grating Type
33 Diced
34 Diced Transmission
43 Wedged
52 Concave
53 Plano
54 Plano Transmission
63 Score and Snap
65 Grism

Substrate Size (BBB)

The 3rd, 4th and 5th characters BBB are numerals that indicate the size of the grating substrate. Size codes are listed on the grating product pages.

Substrate Material (CC)

The 6th and 7th characters CC are letters that indicate the substrate material:

Substrate Material Code CC Substrate Material
AL Aluminum
BF Borosilicate float or equivalent
BK BK-7 glass or equivalent
CU Copper
FL Float glass
FS Fused silica or equivalent
LE Low-expansion glass
SP Special glass (unspecified)
TB BK-7, transmission grade
TF Fused silica, transmission grade
UL Corning ULE® glass
ZD Schott Zerodur®

Coating Type (DD)

The 8th and 9th characters DD are numerals that indicate the type of coating:

Coating Code DD Coating Material Application
01 Aluminum (Al) General purpose applications.
02 Gold (Au) Offers higher reflectivity in the infrared.
03 Magnesium Fluoride (MgF2) Used to prevent oxidation of aluminum (Al) coatings, which helps maintain high reflectivity in the ultraviolet over time.
06 Protected Silver (Ag) Offers higher reflectivity in the visible and near infrared. Silver is protected from tarnishing by a dielectric coating, which helps maintain reflection over time.
07 transmission
09 aluminum with SiO2

Master Grating Groove Parameters (EEE)

The 10th, 11th and 12th characters EEE serve to identify the master grating groove parameters: the groove frequency, blaze angle and blaze wavelength. [In the case of concave gratings, these characters indicate the substrate radius as well]. Master grating catalog codes and the corresponding groove parameters are listed on the diffraction grating product pages.

Master Grating Type (x)

The last character x indicates the type of master grating used to make the product:

Master Grating Type Code x Master Grating Type
C concave holographic
D concave ruled
E echelle
H holographic
R ruled (non-echelle)



  • 53 plano grating
  • 004 → 30 x 30 x 10 mm (substrate dimensions); 26 x 26 mm (ruled area)
  • BK → BK-7 glass or equivalent substrate material
  • 01 → aluminum coating
  • 010 → 600 g/mm, 5.2° blaze angle master grating
  • R → ruled master


  • 53 → plano grating
  • 015 → 110 x 110 x 16 mm (substrate dimensions); 102 x 102 mm (ruled area)
  • FS → fused silica or equivalent substrate material
  • 02 → gold coating
  • 200 → 1200 g/mm, blazed at 250 nm
  • H → plano holographic master


  • 53 → plano grating
  • 028 → 165 x 220 x 35 mm (substrate dimensions); 154 x 206 mm (ruled area)
  • LE → low expansion glass substrate material
  • 06 → protected silver coating 414 → 31.6 g/mm, 76° blaze angle
  • E → echelle master


  • 52 → concave grating
  • 027 → 32 x 32 mm (substrate dimensions); 30 x 30 mm (ruled area)
  • BK → BK-7 glass or equivalent substrate material
  • 03 → aluminum with MgF2 coating
  • 010 → 1200 g/mm, constant-deviation grating, blazed at 250 nm
  • C → concave holographic master