KEWLAB KP17-010 K9 Precision-Grade Pentaprism

Overview

The KEWLAB KP17-010 is a high-precision pentaprism fabricated from homogenously annealed K9 borosilicate crown glass—a material widely specified in metrology-grade optical systems for its excellent transmission (≥91% per surface uncoated), low bubble/inclusion content, and thermal stability (dn/dT ≈ 2.2 × 10⁻⁶ /°C). Unlike roof prisms or mirror-based right-angle reflectors, the pentaprism provides a fixed 90° beam deviation independent of angular alignment error—making it indispensable in applications requiring absolute directional stability, such as autocollimation setups, optical axis alignment in interferometers, and coordinate-measuring machine (CMM) laser guidance systems. Its monolithic structure eliminates sensitivity to polarization and avoids ghost reflections common in multi-element folded paths. The prism operates across the visible spectrum (380–780 nm), with optimized performance at the helium–neon reference wavelength (632.8 nm), where surface figure is verified to λ/2 RMS.

Key Features

• Monolithic K9 optical glass substrate with certified annealing history to minimize internal stress birefringence and ensure long-term dimensional stability under laboratory temperature fluctuations.
• Strict dimensional control: all three orthogonal edge lengths (A, B, C) held to +0.0 / −0.2 mm tolerance, ensuring repeatability in kinematic mounting fixtures and precision jig assemblies.
• Optimized geometry: diagonal dimension D = 10.82 mm confirms nominal 90° deviation within ±10 arcseconds across the clear aperture, validated via interferometric null testing.
• Dual-coating architecture: reflective faces feature vacuum-deposited aluminum (R ≥ 88% @ 550 nm) with matte black paint overcoat to suppress stray light and reduce cavity resonance effects; input/output faces receive single-layer MgF₂ anti-reflection coating (R < 1.5% average, 400–700 nm).
• Surface quality compliant with ISO 10110-7: 2017 standards for scratch-dig (3–4 level), verified using calibrated comparison standards under controlled illumination.

Sample Compatibility & Compliance

The KP17-010 is designed for integration into Class I and Class II optical benches per ANSI Z80.10 and ISO 10110-1. Its surface figure (λ/2 @ 632.8 nm) and surface quality meet typical requirements for alignment-grade components used in ISO/IEC 17025-accredited calibration laboratories. While not supplied with formal certification documentation, the prism’s manufacturing traceability aligns with general-purpose optical component procurement practices under MIL-PRF-13830B and JIS B 7151. It is compatible with standard kinematic mounts (e.g., SM1-threaded cage systems, Thorlabs PRM1Z8), and its edge deletion (<0.25 mm × 45°) prevents chipping during handling and clamping.

Software & Data Management

As a passive optical component, the KP17-010 requires no embedded firmware, drivers, or software interface. However, its geometric and coating specifications are fully compatible with industry-standard optical design software environments—including Zemax OpticStudio (sequential mode), CODE V, and FRED—for accurate ray tracing, stray-light analysis, and system-level tolerance modeling. Users may import manufacturer-provided STEP or IGES models (available upon request) to simulate thermal expansion effects, mechanical mounting stresses, and polarization-dependent phase shifts in multi-prism configurations.

Applications

• Autocollimator-based alignment of optical axes in telescopes, laser cavities, and synchrotron beamlines.
• Fixed-angle beam folding in compact spectrometer designs where space constraints prohibit mirror stacks.
• Reference path definition in Michelson and Twyman–Green interferometers requiring polarization-insensitive, zero-phase-shift redirection.
• Calibration artifacts for digital theodolites and robotic total stations in geodetic instrumentation labs.
• Educational optics kits for demonstrating image erectness preservation and parallax-free reflection principles in undergraduate physics laboratories.

FAQ

Does this pentaprism preserve image handedness?
Yes—the pentaprism inverts the image vertically but maintains lateral orientation, resulting in an erect (non-reversed) image, unlike a single mirror or right-angle prism.
Can it be used with UV or NIR wavelengths?
K9 glass transmits effectively from ~350 nm to ~2.0 µm; however, the MgF₂ AR coating is optimized for 400–700 nm. For UV applications below 380 nm, bare surfaces or custom coatings (e.g., LaF₃/MgF₂) are recommended.
Is the aluminum coating protected against oxidation in ambient lab air?
Yes—the matte black paint overcoat acts as both a mechanical barrier and environmental sealant, extending functional lifetime beyond 5 years under ISO 14644-1 Class 8 cleanroom conditions.
What is the maximum permissible incident beam diameter?
The clear aperture is defined by the smallest cross-section along the optical path—approximately Ø9.2 mm—and should be used with collimated beams ≤8 mm diameter to avoid vignetting and maintain wavefront fidelity.
Are calibration certificates or test reports available?
Standard units ship without individual test reports; however, batch-level metrology data (interferometric surface maps, spectral reflectance scans) can be provided upon request for qualifying orders (≥10 pcs).