Right-Angle Kinematic Mount for Off-Axis Parabolic Mirrors

  • Kinematic Mount for Ø1" Off-Axis Parabolic Mirrors
  • ±4° of Kinematic Pitch/Yaw Adjustment
  • Cage System and Lens Tube Compatible
  • 1/4"-20 (M6) Taps for Post Mounting


Kinematic Mount for
Ø1" Off-Axis Parabolic Mirrors

Mounting Plate

Off-Axis Parabolic Mirror
(Sold Separately)

Housing Body

Application Idea

The KCB1P Mount is 30 mm Cage System
and SM1 Lens Tube Compatible.
(Shown with CPA1 Alignment Cage Plate and
Off-Axis Parabolic Mirror, Each Sold Separately)

Related Items

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Three 4-40 screws on the back of the mounting plate hold the mirror in place, while the lock screw secures the mounting plate to the housing body.

Click to Enlarge

Beam Path Inside KCB1P Mount
(OAP Mirror Sold Separately)


The KCB1P(/M) right-angle mount provides pitch and yaw adjustment for a Ø1" (Ø25.4 mm) off-axis parabolic (OAP) mirror mounted on a plate that positions the surface of the mirror at a 45° angle. The ports are equipped with SM1-threaded (1.035"-40) bores and four 0.25" (6.35 mm) deep smooth bore holes spaced to mate with our 30 mm cage system. The cage rods are secured by eight setscrews using a 5/64" (2.0 mm) hex key or balldriver. This design allows multiple 30 mm cage components to be directly interfaced without the need for ERSCB ER Rod Adapters. The kinematic pitch and yaw adjustment plate is actuated with 100 TPI (Threads Per Inch) adjustment screws that provide an angular resolution of 7.6 mrad/rev. The knob on each adjuster is removable. While the optic face is nominally centered within the mount, the third adjuster can be used for fine tuning the position along the optical axis.

Click to Enlarge

The ports on the front of the mount are SM1-threaded. The collimated beam port is labeled with the '∞' symbol.

Three captive 4-40 cap screws in the optic mounting plate are used to secure the Ø1" (Ø25.4 mm) off-axis parabolic mirror using a 5/64" (2.0 mm) hex key or balldriver. The rear-loading, removable mounting plate features our ball and V-groove design that allows it to be precisely kinematically positioned on the body of the mount. The plate and mount are held together using pairs of rare-earth magnets. Once mounted, the plate can be firmly secured in place using the captive locking screw with 5/64" (2.0 mm) hex on the back. The rear-loading design ensures that the optic remains accessible even after the mount is fitted with cage rods or lens tubes. The back of the mounting plate offers an engraved label for marking details about the installed mirror such as the focal length or part number. The mounting plate also features through bores for OAP mirrors with holes for the focused or collimated beams, though we do not currently stock these mirrors in a Ø1" form factor. To request a quote for custom Ø1" OAP mirrors with holes, please contact Tech Support.

Other Mounting Options
Our off-axis parabolic mirrors can also be mounted directly in our smooth bore kinematic mirror mounts for round optics, such as the KM100 Ø1" Optic Mount or POLARIS-K1S5 Ultra-Stable Ø1" Optic Mount.

Posted Comments:
user  (posted 2024-01-09 09:15:12.003)
Hi, I have a question to the Right-Angle Kinematic Mount for Off-Axis Parabolic Mirrors (KCB1P/M). For the third adjuster which can be used for fine tuning the position along the optical axis, I read: Z-Axis Translation Using All Three Adjusters: ±0.12" (±3.0 mm). What does this really mean? Could you send me a drawing that explains what the function? I think this option is very important for me. Kind regards
jpolaris  (posted 2024-01-26 12:19:47.0)
Thank you for contacting Thorlabs. Using all three adjusters will produce a translation along an axis that is oriented 45° with respect to the optical axis. We refer to this axis as the "Z-axis" in the description of this product. Using the third adjuster on its own would not produce translation strictly in the optical axis. The maximum component of translation along the optical axis is ± 3.0 mm * Cos(45°) = ± 2.12 mm. Due to this 45° angle, the centration of the beam on the mirror will be impacted by translation in the Z-axis. This can be helpful in the alignment process. I have reached out to you directly about this.
user  (posted 2021-04-27 10:05:34.12)
Is it possible to make this mount for 2 inch OAPM motorized?.
sebastian.schaefer  (posted 2019-03-04 13:05:11.703)
Can you also offer something similar to KCB1P/M but for 2'' OAPs?
llamb  (posted 2019-03-04 03:35:11.0)
Thank you for your feedback! This idea is already in discussion in our internal product forum, as we are hoping to develop this as a new product for our 60 mm cage systems.
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Right-Angle Kinematic Mount for Off-Axis Parabolic Mirrors

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
KCB1P Support Documentation
KCB1PCustomer Inspired! Right-Angle Kinematic OAP Mirror Mount, 30 mm Cage System and SM1 Compatible, 1/4"-20 Mounting Holes
+1 Qty Docs Part Number - Metric Price Available
KCB1P/M Support Documentation
KCB1P/MCustomer Inspired! Right-Angle Kinematic OAP Mirror Mount, 30 mm Cage System and SM1 Compatible, M6 Mounting Holes