KEWLAB KP23-015 UV Fused Silica Right-Angle Prism

Overview

The KEWLAB KP23-015 is a precision-engineered right-angle prism fabricated from UV-grade fused silica—a material selected for its exceptional transmission (>99.5% per surface) across the deep ultraviolet spectrum (185–2100 nm), low thermal expansion coefficient (5.5 × 10⁻⁷ /°C), and high laser-induced damage threshold (LIDT > 5 J/cm² at 355 nm, 10 ns, 20 Hz). Designed explicitly for demanding laser beam steering, folding, and polarization-insensitive 90° deviation applications in UV laser systems—including Nd:YAG third-harmonic generation (355 nm), excimer lasers (193 nm, 248 nm), and ultrafast Ti:sapphire amplifier compressors—the KP23-015 operates on total internal reflection (TIR) principles when used uncoated, but incorporates a high-performance V-type anti-reflection coating optimized for 355 nm to minimize insertion loss and suppress ghost reflections. Its λ/10 surface flatness and sub-arcsecond angular tolerance ensure minimal wavefront distortion (<0.05 wave RMS) and beam deviation stability under thermal cycling or mechanical mounting stress—critical for interferometric alignment, cavity coupling, and optical parametric oscillator (OPO) pump path integration.

Key Features

• UV-transmitting fused silica substrate with OH-content < 1 ppm, enabling high transmission down to 185 nm without solarization-induced degradation
• Strict dimensional control: 15.0 mm cube geometry with ±0.1 mm tolerance on all edges, facilitating reproducible kinematic mounting in multi-prism assemblies
• Hypotenuse face coated with a single-wavelength V-coating (centered at 355 nm), achieving average reflectance < 0.25% across ±5 nm bandwidth and residual absorption < 0.08% (measured via photothermal common-path interferometry)
• Surface quality rated to MIL-PRF-13830B 10–20 scratch-dig specification, verified via automated dark-field inspection at 50× magnification
• Chamfered edges (0.2–0.5 mm × 45°) reduce edge chipping risk during handling and mitigate stray light via controlled diffraction suppression
• Validated wedge error < 5 arcseconds ensures collimation retention after double-pass configurations—essential for retroreflector-based cavity length stabilization

Sample Compatibility & Compliance

The KP23-015 is compatible with standard optomechanical mounts including SM1-threaded cage systems, kinematic mirror mounts (e.g., Thorlabs KM100), and vacuum-compatible stainless-steel prism holders. It meets RoHS Directive 2011/65/EU and REACH Annex XVII requirements for heavy metal content. While not certified to ISO 10110-7 for laser optics classification, its fabrication process adheres to ISO 10110-1 (drawing specification) and ISO 10110-3 (surface imperfection limits). For GMP-compliant cleanroom integration (ISO Class 5 or better), optional clean-packaging in nitrogen-purged, static-dissipative bags is available upon request. No biocompatibility or medical device certification applies, as this component is intended solely for laboratory and industrial optical instrumentation use.

Software & Data Management

As a passive optical component, the KP23-015 requires no embedded firmware, drivers, or software interface. However, its geometric and coating specifications are fully exportable in Zemax OpticStudio (ZOS) and CODE V native format via provided .ZMX lens file—containing accurate dispersion data (Sellmeier coefficients for UV fused silica), coating stack definition (layer thicknesses and refractive indices), and mechanical tolerancing parameters for Monte Carlo sensitivity analysis. All metrology reports—including interferometric surface map (Zygo GPI), spectral reflectance curve (PerkinElmer Lambda 950), and LIDT test logs—are archived digitally and supplied with batch traceability (lot number, coating run ID, interferogram timestamp) to support GLP audit trails and ISO/IEC 17025-compliant calibration documentation.

Applications

• Beam folding in compact Q-switched Nd:YAG laser cavities operating at 355 nm
• Pump delivery optics for UV-pumped OPOs and Raman shifters requiring high polarization extinction ratio preservation
• Reference arms in UV Michelson or Mach–Zehnder interferometers for semiconductor mask inspection metrology
• Input/output couplers in ultrafast amplifier compressor stages using grating–prism pairs
• Alignment fiducials in EUV lithography prototype beamlines where outgassing and particulate shedding must be minimized
• Calibration standards for UV radiometric systems traceable to NIST SRM 2065 (fused silica transmission reference)

FAQ

Is the KP23-015 suitable for high-repetition-rate ultrafast lasers (e.g., 1 kHz, 35 fs pulses)?

Yes—its UV fused silica substrate exhibits negligible group delay dispersion (GDD ≈ −15 fs²/mm at 355 nm) and has been tested to maintain wavefront fidelity after >10⁹ shots at 1 kHz, 355 nm, 1 mJ/pulse.
Can the V-coating withstand exposure to ozone or humid environments?

The MgF₂/TiO₂ multilayer stack is hermetically sealed and passes 96-hour 85°C/85% RH IEC 60068-2-78 testing; however, prolonged immersion or condensation is not recommended.
What mounting recommendations prevent stress-induced birefringence?

Use three-point contact with compliant pads (e.g., Viton® O-rings) and torque screws to ≤0.15 N·m; avoid clamping directly on polished faces.
Is custom coating available for other UV wavelengths (e.g., 266 nm or 193 nm)?

Yes—custom broadband or narrowband AR coatings can be applied; lead time increases by 3–4 weeks and minimum order quantity is 5 units.
Does KEWLAB provide interferometric certification for individual prisms?

Standard shipment includes batch-level interferograms; individual prism certification (with Zernike coefficient report) is available as a value-added service (additional cost applies).