McPherson precision parabolic mirror mandrel 1 meter focal length

Product Description

Rare McPherson Precision Parabolic Mirror Mandrel – 16″ Diameter On-Axis Parabolic Mirror Mandrel – 1 Meter Focal Length – For Replication of Model 2061 Mirrors – 3″ Edge Thickness – Pristine Condition

This substantial on-axis parabolic mirror is a master mandrel that was used for the epoxy replication of off-axis parabolic (OAP) mirrors in McPherson’s flagship Model 2061 1-meter focal length Czerny-Turner monochromator/spectrometer —an instrument that remains in production today . The label marking clearly reads “For replication of 2061 mirrors” , verifying its original manufacturing role, while the edge marking “0° AOC” (0° Angle Off Center) confirms its on-axis (zero-degree offset) design as the central, symmetric parent parabola from which angled off-axis sections were replicated. An additional marking “LARGE SUB” (Large Substrate) emphasizes its role as a master blank.

McPherson’s Model 2061 is a 1-meter focal length instrument that provides an excellent blend of throughput and spectral resolution, making it a staple of laboratory and experimental spectroscopy . While modern Model 2061 units have transitioned to directly polished off-axis parabolic (OAP) optics for production efficiency , this shift has made original replication mandrels like this one exceptionally rare and sought-after on the surplus market. As a genuine internal laboratory tool from McPherson—rarely seen outside their facilities—it represents a unique piece of precision optics history and is in pristine condition with a clean optical surface, no chips, deep scratches, or visible defects.

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Key Specifications

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McPherson Heritage & Historical Significance

McPherson Inc. has been a leader in the design and manufacture of vacuum ultraviolet and high-resolution spectroscopy instrumentation for decades. Their Model 2061 1-meter Czerny-Turner monochromator/spectrometer is a cornerstone instrument in laboratories worldwide, known for its excellent spectral resolution, sharp symmetric line profiles, and high efficiency .

The Model 2061 is available in two versions: the standard version using spherical optics, and the “A” version which uses hand-polished master off-axis parabolic optics to best image small entrance images . This mandrel is directly tied to the production of those precision off-axis parabolic mirrors, representing the master tooling from which operational OAPs were replicated.

While McPherson now offers directly polished OAPs in their current instruments , the replication mandrels like this one have become exceptionally rare. They offer a unique window into the manufacturing processes of high-precision scientific instrumentation and represent a tangible piece of optical fabrication history.

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Technical Background: Replication Mandrels

In optical replication processes, a master mandrel with a precision-polished surface is used as a mold. A thin layer of epoxy bonds a replica substrate to the master’s surface, and after curing, the replica is separated, carrying the precise surface figure of the master. This technique allows for the production of multiple identical high-precision optics without re-polishing each one individually.

This mandrel was specifically used for replicating the off-axis parabolic mirrors employed in the Model 2061’s “A” version, which provides superior imaging of small entrance images . The on-axis design (0° AOC) indicates this is the parent parabola from which off-axis sections were derived.

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Applications & Uses

Optical Replication Master:

• Perfect for producing lightweight replicated off-axis parabolic mirrors using epoxy/resin methods in custom optics fabrication

• Could serve as a master for small-scale production or research into optical replication techniques

Astronomical Telescope Primary:

• Suited as a fast 16″ f/2.5 Newtonian primary for wide-field imaging in custom Dobsonian or other reflector telescopes

• The 1-meter focal length offers excellent light-gathering capability for deep-sky observations

Large Collimator/Beam Director:

• Ideal for laser labs, interferometry, schlieren imaging, or high-power optics testing requiring large-aperture collimated beams

• The uncoated surface allows for custom coating application tailored to specific wavelengths

Scientific Instrumentation:

• Integration into custom spectrometers, beam expanders, monochromators, or high-resolution spectroscopy systems

• Could be used as a primary mirror in custom-built research instruments

Educational/Collector Piece:

• Rare historical artifact for optics labs, universities, museums, or spectroscopy collectors valuing McPherson’s legacy

• Demonstrates precision optical fabrication techniques and the history of scientific instrumentation

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Condition

⚠ HANDLING NOTE: This is a large, heavy (approx. 60 lbs), precision optical component. Handle with extreme care using appropriate lifting techniques. Always handle by the edges with clean gloves. Never touch the polished optical surface. Store in a clean, dry, stable environment when not in use.