2 inch N-BK7 optical wedge prism 2.3 degree

Product Description

Surplus Research Lab 2″ (50.8mm) N-BK7 Optical Wedge Prism/Window, ~2.3° Wedge, Uncoated – Excellent Condition

A high-quality optical wedge prism sourced directly from a research laboratory surplus inventory. With a 2″ (50.8mm) diameter, precision-polished N-BK7 substrate, and a substantial ~2.3° wedge angle, this component delivers controlled beam deviation while eliminating etalon fringes and parasitic back-reflections—essential for clean, stable optical systems. Excellent condition, ready for immediate deployment.

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🔍 Key Specifications:

📐 Dimensions & Geometry:

• Diameter: 2.0″ (50.8 mm) – standard mounting compatibility

• Design: Plano-plano wedge – one strictly flat surface, one plano with precision wedge

• Wedge Angle: ~2.3° (calculated from edge thickness differential)

• Beam Deviation: ~1.2° at 589 nm (dependent on index, Snell’s law)

• Edge Thickness: ~3.5 mm (thin edge) to ~5.5 mm (thick edge)

• Edge Marking: Handwritten red “26 ^” – caret arrow points to thicker edge for instant orientation

💎 Substrate & Surface:

• Material: N-BK7 optical glass – borosilicate crown, excellent homogeneity

• Transmission Range: 350–2000 nm – deep blue to near-IR

• Surface Quality: High research-grade polish – λ/10 or better flatness (typical for lab optics)

• Surface Finish: Appears flawless under inspection – no scratches, chips, or sleeks

• Coating: Uncoated – ~4% natural reflectivity per surface, no wavelength restrictions

✅ Condition:

• Optical Surfaces: Excellent – pristine, no visible defects

• Edges: Clean, precision-ground, no chips

• Origin: University/research laboratory surplus – professionally handled and stored

• Includes: Wedge only – no mounting hardware

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⚙️ Why This Optical Wedge is Exceptional:

🔬 Research-Grade Pedigree:
This is not a commercial catalog surplus item—it is a laboratory-selected optical component from an active research environment. The λ/10 surface quality and precise wedge fabrication reflect genuine research-grade specifications.

📏 Substantial 2.3° Wedge – Beyond Standard “Anti-Fringe”:
Most commercial “wedged windows” offer only 30–60 arcminutes (0.5–1.0°) of wedge—barely sufficient for etalon suppression. This ~2.3° wedge provides:

• Complete elimination of interference fringes – no residual etalon effects

• Significant beam deviation – useful for intentional steering, not just parasitic prevention

• Laser cavity feedback suppression – prevents back-reflections into gain media

• Clear separation of front/back surface reflections – simplifies alignment

🎯 Instant Orientation – Lab-Marked Thick Edge:
The handwritten “26 ^” marking with caret arrow pointing to thick edge is a professional lab practice:

• No guesswork – thick edge identified immediately

• Consistent setup – reproduceable deviation direction

• Time-saving – no need to measure or calculate orientation

💎 Uncoated N-BK7 – Maximum Flexibility:

• Broadband utility – single component works from 350 nm to 2 µm

• No coating to damage – clean with standard solvents, no AR limitations

• Predictable 4% reflectivity – ideal for beam sampling and power monitoring

• Custom coating ready – apply your own AR/HR for specific wavelengths

🔬 λ/10 Surface Quality:
This is not a workshop-grade window—the λ/10 flatness specification indicates:

• Minimal wavefront distortion – preserves beam quality

• Interferometry-capable – suitable for reference-grade applications

• Research-grade fabrication – not commodity production

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🛠️ Applications & Uses:

💫 Controlled Beam Deviation & Steering:

• Intentional beam offset in optical trains – no tip/tilt mount required

• Laser beam steering for alignment and positioning

• Beam sampler – use front-surface reflection for power monitoring

• Optical isolator substitute – prevent feedback into laser cavities

🔬 Etalon Fringe & Back-Reflection Suppression:

• Eliminate interference fringes in imaging and spectroscopy systems

• Prevent parasitic etalons between parallel surfaces in multi-element optics

• Suppress feedback into laser diodes, fiber lasers, and gas lasers

• Clean up beam profiles – no modulation from unintentional cavities

⚙️ Risley Prism Configuration:

• Pair with second wedge for variable beam steering (Risley prism scanner)

• Two-axis beam control with simple rotation adjustments

• Compact, vibration-resistant alternative to mirror gimbals

🔭 Interferometry & Metrology:

• Beam steering in Michelson, Mach-Zehnder, and Fizeau interferometers

• Reference beam offset for phase-shifting interferometry

• Shearing interferometry components

🧪 Spectroscopy & Optical Testing:

• Beam displacement in monochromator input optics

• Calibration reference for deviation measurements

• Educational demonstrations – Snell’s law, prism deviation, dispersion

🎓 Research & Education:

• University teaching labs – demonstrate wedge deviation and total internal reflection limits

• Advanced laboratory courses – build Risley beam steerers

• Optics prototyping – rapid configuration of beam paths