Pellin Broca Prism

Ideal for Wavelength Separation of a Beam of Light
Selected Wavelength Deviated by 90°

ADBU-20

ADB-10

Application Idea

ADB-10 Mounted on a
PRMTZ8 Motorized Rotation Stage

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Overview
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Prism Guide

Common Specifications
Dimensional Tolerance	±0.2 mm
Angular Tolerance	±3 min
Surface Flatness	λ/8
Surface Quality	20-10 Scratch Dig

Pellin Broca Prism Drawing
Figure 1.1 Pellin Broca Prism Top View (Left) and Side View (Right)

Item #	A	B	H	Φ
ADB-10	19.0 mm	33.0 mm	11.0 mm	78° 26'
ADB-20	38.0 mm	66.0 mm	22.0 mm	78° 26'
ADBU-10	19.0 mm	33.0 mm	11.0 mm	78° 26'
ADBU-20	38.0 mm	66.0 mm	22.0 mm	78° 26'
ADBV-10	19.0 mm	33.0 mm	11.0 mm	78° 26'

Features

Ideal for Wavelength Seperation of a Beam of Light
Selected Wavelength Deviated by 90°

Pellin Broca Prisms can be used to separate the harmonics of a laser beam or compensate for group velocity dispersion. The light enters and exits the prism near Brewster's angle, which minimizes reflection losses in p-polarized light. Since the beam undergoes one total internal reflection before exiting the prism, the angle between the input and exit beams is 90° plus a small angle due to dispersion. The dispersion is less for longer wavelengths.

Figure 1.2 Dispersion Through a Pellin Broca Prism

As the prism is rotated about point R in Figure 1.2, the wavelength of light that is deviated by 90° changes even though the geometry and relative positions of the input and output beams remains unchanged.

Zemax Files
Click on the red Document icon next to the item numbers below to access the Zemax file download. Our entire Zemax Catalog is also available.

Item #	Material	Design Spectrum λ_low to λ_high^b	Angular Separation Between λ_low & λ_high	Brewster's Angle θ_B for λ_low to λ_high	Distance D (Rotation Point)	Aperture (Square)
ADB-10	N-BK7^a	380 nm - 2.5 μm	5.42°	56.1° - 56.9°	16.1 mm	10 mm
ADB-20	N-BK7^a	380 nm - 2.5 μm	5.42°	56.1° - 56.9°	32.2 mm	20 mm
ADBU-10	UV Fused Silica^a	190 - 425 nm	11.47°	55.7° - 57.4°	16.1 mm	10 mm
ADBU-20	UV Fused Silica^a	190 - 425 nm	11.47°	55.7° - 57.4°	32.2 mm	20 mm
ADBV-10	Calcium Fluoride^a	180 - 250 nm	5.23°	55.7° - 56.6°	16.1 mm	10 mm

Click Link for Detailed Specifications on the Substrate Glass
While the prisms were designed for these wavelengths, they can be used outside of these ranges.

Posted Comments:

user (posted 2025-07-07 11:32:11.343)

What do you mean by the angular separation between λ_min and λ_max? Furthermore, is it possible to provide a graph that associates a specific rotation angle of the prism with the wavelength of the beam deviated by 90°?

EGies (posted 2025-07-09 12:11:10.0)

The angular separation between λ_low and λ_high defines the difference in output beam angle between the shortest wavelength in the design spectrum to the longest. For example, for the ADB-10, this means that light with a wavelength of 380nm is output from the prism at an angle 5.42 degrees deviated from light with a wavelength of 2.5um. The Zemax file for each prism is available in its respective “Drawings and Documents” for further modeling.

user (posted 2023-10-13 16:34:06.207)

Do you have a technical drawing showing where the rotation point is in regards to the other facets? Also the lengths of all the sides?

cdolbashian (posted 2023-10-27 11:25:20.0)

Thank you for reaching out to us with this inquiry! All of the requested information is shown within the "Overview" tab on the product page. I have reached out to you directly to share the explicit values with you.

jon.freeman (posted 2016-01-13 11:01:15.14)

What is the angular tolerance of the "fine ground" sides to the polished faces -we want to use the prism as an angular reference

besembeson (posted 2016-01-18 10:31:55.0)

Response from Bweh at Thorlabs USA: I will contact you with this information please.

tcohen (posted 2012-03-09 13:30:00.0)

Response from Tim at Thorlabs: We are able to offer custom coatings on some of our optics. I have contacted you directly to get more information.

michael.renner (posted 2012-03-07 10:12:12.0)

Do you also offer a coated version of ADB-10 when working with s-polarized light (antireflection between 420 - 580nm)?

Selection Guide for Prisms

Thorlabs offers a wide variety of prisms, which can be used to reflect, invert, rotate, disperse, steer, and collimate light. For prisms and substrates not listed below, please contact Tech Support.

Beam Steering Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Applications
Right Angle Prisms	N-BK7, UV Fused Silica, Calcium Fluoride, or Zinc Selenide	90°	90°	No	90° reflector used in optical systems such as telescopes and periscopes.
Right Angle Prisms	N-BK7, UV Fused Silica, Calcium Fluoride, or Zinc Selenide	180°	180°	No	180° reflector, independent of entrance beam angle. Acts as a non-reversing mirror and can be used in binocular configurations.
TIR Retroreflectors (Unmounted and Mounted) and Specular Retroreflectors (Unmounted and Mounted)	N-BK7	180°	180°	No	180° reflector, independent of entrance beam angle. Beam alignment and beam delivery. Substitute for mirror in applications where orientation is difficult to control.
Unmounted Penta Prisms and Mounted Penta Prisms	N-BK7	90°	No	No	90° reflector, without inversion or reversal of the beam profile. Can be used for alignment and optical tooling.
Roof Prisms	N-BK7	90°	90°	180^o Rotation	90° reflector, inverted and rotated (deflected left to right and top to bottom). Can be used for alignment and optical tooling.
Unmounted Dove Prisms and Mounted Dove Prisms	N-BK7	No	180°	2x Prism Rotation	Dove prisms may invert, reverse, or rotate an image based on which face the light is incident on. Prism in a beam rotator orientation.
Unmounted Dove Prisms and Mounted Dove Prisms	N-BK7	180°	180°	No	Prism acts as a non-reversing mirror. Same properties as a retroreflector or right angle (180° orientation) prism in an optical setup.
Wedge Prisms	N-BK7	Models Available from 2° to 10°	No	No	Beam steering applications. By rotating one wedged prism, light can be steered to trace the circle defined by 2 times the specified deviation angle.
Wedge Prisms	N-BK7	Models Available from 2° to 10°	No	No	Variable beam steering applications. When both wedges are rotated, the beam can be moved anywhere within the circle defined by 4 times the specified deviation angle.
Coupling Prisms	Rutile (TiO₂) or GGG	Variable^a	No	No	High index of refraction substrate used to couple light into films. Rutile used for n_film > 1.8 GGG used for n_film < 1.8

Depends on Angle of Incidence and Index of Refraction

Dispersive Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Applications
Equilateral Prisms	F2, N-F2, N-SF11, Calcium Fluoride, or Zinc Selenide	Variable^a	No	No	Dispersion prisms are a substitute for diffraction gratings. Use to separate white light into visible spectrum.
Dispersion Compensating Prism Pairs	Fused Silica, Calcium Fluoride, SF10, or N-SF14	Variable Vertical Offset	No	No	Compensate for pulse broadening effects in ultrafast laser systems. Can be used as an optical filter, for wavelength tuning, or dispersion compensation.
Pellin Broca Prisms	N-BK7, UV Fused Silica, or Calcium Fluoride	90°	90°	No	Ideal for wavelength separation of a beam of light, output at 90°. Used to separate harmonics of a laser or compensate for group velocity dispersion.

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Equilateral Prisms

F2, N-F2,
N-SF11,
Calcium Fluoride,
or Zinc Selenide

Variable^a

Dispersion prisms are a substitute for diffraction gratings.

Use to separate white light into visible spectrum.

Dispersion Compensating Prism Pairs

Fused Silica, Calcium Fluoride, SF10, or N-SF14

Variable Vertical Offset

Compensate for pulse broadening effects in ultrafast laser systems.

Can be used as an optical filter, for wavelength tuning, or dispersion compensation.

Pellin Broca Prisms

N-BK7,
UV Fused Silica,
or Calcium Fluoride

90°

Ideal for wavelength separation of a beam of light, output at 90°.

Used to separate harmonics of a laser or compensate for group velocity dispersion.

Depends on Angle of Incidence and Index of Refraction

Beam Manipulating Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Illustration	Applications
Anamorphic Prism Pairs	N-KZFS8 or N-SF11	Variable Vertical Offset	No	No		Variable magnification along one axis. Collimating elliptical beams (e.g., laser diodes) Converts an elliptical beam into a circular beam by magnifying or contracting the input beam in one axis.
Axicons (UVFS, ZnSe)	UV Fused Silica or Zinc Selenide	Variable^a	No	No		Creates a conical, non-diverging beam with a Bessel intensity profile from a collimated source.

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Anamorphic Prism Pairs

N-KZFS8 or
N-SF11

Variable Vertical Offset

Variable magnification along one axis.

Collimating elliptical beams (e.g., laser diodes)

Converts an elliptical beam into a circular beam by magnifying or contracting the input beam in one axis.

Axicons (UVFS, ZnSe)

UV Fused Silica
or Zinc Selenide

Variable^a

Creates a conical, non-diverging beam with a Bessel intensity profile from a collimated source.

Depends on Prism Physical Angle

Polarization Altering Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Applications
Glan-Taylor, Glan-Laser, and α-BBO Glan-Laser Polarizers	Glan-Taylor: Calcite Glan-Laser: α-BBO or Calcite	p-pol. - 0° s-pol. - 112°^a	No	No	Double prism configuration and birefringent calcite produce extremely pure linearly polarized light. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Rutile Polarizers	Rutile (TiO₂)	s-pol. - 0° p-pol. absorbed by housing	No	No	Double prism configuration and birefringent rutile (TiO₂) produce extremely pure linearly polarized light. Total Internal Reflection of p-pol. at the gap between the prisms while s-pol. is transmitted.
Double Glan-Taylor Polarizers	Calcite	p-pol. - 0° s-pol. absorbed by housing	No	No	Triple prism configuration and birefringent calcite produce maximum polarized field over a large half angle. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Glan Thompson Polarizers	Calcite	p-pol. - 0° s-pol. absorbed by housing	No	No	Double prism configuration and birefringent calcite produce a polarizer with the widest field of view while maintaining a high extinction ratio. Total Internal Reflection of s-pol. at the gap between the prism while p-pol. is transmitted.
Wollaston Prisms and Wollaston Polarizers	Quartz, Magnesium Fluoride, α-BBO, Calcite, Yttrium Orthovanadate	Symmetric p-pol. and s-pol. deviation angle	No	No	Double prism configuration and birefringent calcite produce the widest deviation angle of beam displacing polarizers. s-pol. and p-pol. deviate symmetrically from the prism. Wollaston prisms are used in spectrometers and polarization analyzers.
Rochon Prisms	Magnesium Fluoride or Yttrium Orthovanadate	Ordinary Ray: 0° Extraordinary Ray: deviation angle	No	No	Double prism configuration and birefringent MgF₂ or YVO₄ produce a small deviation angle with a high extinction ratio. Extraordinary ray deviates from the input beam's optical axis, while ordinary ray does not deviate.
Beam Displacing Prisms	Calcite	2.7 or 4.0 mm Beam Displacement	No	No	Single prism configuration and birefringent calcite separate an input beam into two orthogonally polarized output beams. s-pol. and p-pol. are displaced by 2.7 or 4.0 mm. Beam displacing prisms can be used as polarizing beamsplitters where 90^o separation is not possible.
Fresnel Rhomb Retarders	N-BK7	Linear to circular polarization Vertical Offset	No	No	λ/4 Fresnel Rhomb Retarder turns a linear input into circularly polarized output. Uniform λ/4 retardance over a wider wavelength range compared to birefringent wave plates.
Fresnel Rhomb Retarders	N-BK7	Rotates linearly polarized light 90°	No	No	λ/2 Fresnel Rhomb Retarder rotates linearly polarized light 90°. Uniform λ/2 retardance over a wider wavelength range compared to birefringent wave plates.

S-polarized light is not pure and contains some P-polarized reflections.

Beamsplitter Prisms

Prism	Material	Deviation	Invert	Reverse or Rotate	Illustration	Applications
Beamsplitter Cubes	N-BK7	50:50 splitting ratio, 0° and 90° s- and p- pol. within 10% of each other	No	No		Double prism configuration and dielectric coating provide 50:50 beamsplitting nearly independent of polarization. Non-polarizing beamsplitter over the specified wavelength range.
Polarizing Beamsplitter Cubes	N-BK7, UV Fused Silica, or N-SF1	p-pol. - 0° s-pol. - 90°	No	No		Double prism configuration and dielectric coating transmit p-pol. light and reflect s-pol. light. For highest polarization use the transmitted beam.

Prism

Material

Deviation

Invert

Reverse or Rotate

Illustration

Applications

Beamsplitter Cubes

N-BK7

50:50 splitting ratio, 0° and 90°

s- and p- pol. within 10% of each other