# Specifications

The shape of the standard CRE is a rectangular parallelepiped with
edges along the CRE
coordinate axes {X, Y, Z} and lengths *d _{X}*,

*d*and

_{Y}*d*, correspondingly.

_{Z}We offer three types of CRE base cross-section *d _{X}*
×

*d*: S = 4 × 3mm

_{Y}^{2}, M = 4 × 6mm

^{2}and L = 8 × 6mm

^{2}. The tolerances are -0.1/+0.3mm.

Lambda-parameters can be requested in the range from 50μm to 500μm. We will inform you about the closest available value. This parameter is measured individually for each one CRE with accuracy less than 1%.

The misalignment angle between the optical axis and the normal vector of the CRE base is critical for some experiments. For our standard products this angle is less than 2mrad and is controlled at 633nm.

The CRE bases are parallel with maximum deviation of 10 arc seconds. Their optical finish is valued as scratch-dig 10-5.

The next characteristics of our products can be useful for the optical engineering purpose:

The length *d _{Z}* of one CRE with known -parameter is
evaluated as

*d*62.

_{Z}The resolution is defined for a diffraction limited incident beam as the maximum of which can be measured in the real isomomentum plane of the beam after CRE; here is the waist radius of the incident beam. We specify the next resolutions at 633nm: 215, 290 and 430 for the cross-sectional types S, M and L, respectively.

We offer two kinds of options. Option1 refers to CREs, which
crystal host is doped with laser ion; only Nd^{3+} ion
is available at present. Option2 refers to CREs with
antireflective coatings; the spectral ranges 1030÷1080nm and
620÷680nm are usually stock available.

The above specified misalignment angle is excessively precise for many experiments like laser oscillation, spinor transformation, etc. If you are interested for out-of-specs samples, contact us at sales@croptics.de.