BK7 Optical Window
Chenyu Optics supplies custom BK7 and N-BK7 optical windows according to customer drawings, including specified material grade, dimensions, thickness, parallelism, surface figure, surface quality, clear aperture, bevel or chamfer and coating requirements. Uncoated, broadband AR, V-coating and application-specific coating options are available for visible and near-infrared imaging, laser and measurement systems.
BK7 Optical Window Overview
BK7 Optical Windows are general-purpose components within our Optical Windows range, used to transmit visible and near-infrared light while protecting internal optics.
BK7 and N-BK7 are crown optical glasses suited to cost-sensitive visible and NIR systems. See our BK7 Optical Material information for material selection context. For UV transmission or improved thermal stability, fused silica is generally preferred; where hardness, abrasion resistance or harsh-environment durability is more important, sapphire is usually the stronger candidate.
Chenyu Optics supports round, rectangular and Custom Optical Window production according to customer drawings, including material grade, dimensions, thickness, edge geometry, surface and coating requirements for prototype and repeat orders.
Key Advantages of BK7 Optical Window
Imaging, Laser & Optical Instrument Systems
BK7 optical windows are widely used for visible and near-infrared transmission in laser systems, imaging equipment, microscopy systems and scientific research instruments.
Typical Specifications of BK7 Optical Window
| Material Grade | BK7 or N-BK7 optical glass; equivalent or alternative glass grades subject to drawing review |
|---|---|
| Optical Function | Transmitting light while protecting internal optical components |
| Coating Options | Uncoated / Broadband AR Coating / V-Coating / Custom Optical Coating |
| Transmission Range | Approx. 350 nm – 2.5 μm |
| Refractive Index | Approx. 1.517 @ 587.6 nm |
| Dimensions / Diameter | Available upon request according to customer drawing |
| Thickness | Available upon request according to customer drawing |
| Parallelism / Wedge | According to component design and agreed inspection requirements |
| Surface Figure / Flatness | Available according to optical performance requirements; specify aperture and reference wavelength |
| Surface Quality | According to drawing and agreed visual inspection standard |
| Clear Aperture | According to drawing |
| Edge / Bevel / Chamfer | Ground, fine-ground, polished or chamfered according to drawing |
| Inspection | Dimensional, surface, interferometric and spectral inspection as specified and agreed |
Spectral Transmission Curve (Typical)
Why Choose Chenyu Optics for BK7 Optical Window
Chenyu Optics focuses on drawing-based precision optical glass manufacturing for visible and near-infrared systems. We support prototype verification, small-batch production and repeat manufacturing for non-standard BK7 windows.
Manufacturing Capability for BK7 Optical Window
Precision Polishing
Grinding and polishing according to the specified dimensions, parallelism, surface figure, surface quality and clear aperture requirements.
Optical Coating
Broadband AR, V-coating and multi-layer AR coating options for visible and near-infrared applications.
Inspection & Packaging
Specified dimensions are checked with suitable dimensional instruments; surface quality is visually inspected under the agreed standard, surface figure may be verified interferometrically, and coated parts may be spectrally measured. Components are individually protected and packed to reduce contact, contamination and transport damage.
Custom Manufacturing Options for BK7 Optical Window
Dimensions & Geometry
Custom diameter, thickness and clear aperture can be manufactured according to customer drawings, with standard or custom window shapes.
Surface & Mechanical Quality
Parallelism, surface figure, surface quality, clear aperture and bevel or chamfer are reviewed according to the drawing, optical performance and agreed inspection requirements.
Coating & Wavelength Design
Uncoated, broadband AR, V-coating, multi-layer AR and custom optical coatings can be specified for visible and near-infrared applications.
BK7 Window Material Comparison
| BK7 / N-BK7 | Fused Silica | Sapphire | Borosilicate Glass | |
|---|---|---|---|---|
| Transmission | Visible to NIR, approx. 350 nm – 2.5 μm | UV to NIR, approx. 0.18 – 2.5 μm | UV to MWIR, commonly 0.2 – 5.5 μm | Visible range, approx. 350 nm – 2.0 μm |
| Refractive Index | Approx. 1.517 @ 587.6 nm | Approx. 1.458 @ 587.6 nm | Approx. 1.76 | Approx. 1.47 @ 587.6 nm |
| Mechanical Notes | Good mechanical stability, cost-effective, moderate hardness | High thermal stability, low thermal expansion, chemically durable | Very hard and chemically durable | Moderate thermal stability, cost-effective, lower precision homogeneity |
| Typical Use | General-purpose imaging, laser and instrument windows | UV/NIR laser windows, high-power laser optics | Protective windows, harsh environment optics | General protective glazing, low-cost instrument windows |
| Selection Guidance | Choose for general visible/NIR optics when standard optical-glass performance and cost control are priorities. | Choose when UV transmission, low thermal expansion or improved thermal stability is required. | Choose when hardness, abrasion resistance and harsh-environment durability are the main requirements. | Choose for basic protective glazing where optical homogeneity and precision requirements are less demanding. |
Applications of BK7 Optical Window
Laser Systems
Windows for visible and near-infrared laser optical paths.
Imaging Systems
Stable transmission and low distortion for imaging applications.
Microscopy Systems
Precision windows for microscopy and inspection optics.
Optical Instruments
General-purpose windows for optical instrument assemblies.
Machine Vision Systems
Reliable protection windows for machine vision cameras.
Scientific Research Equipment
Precision windows for research and laboratory optical setups.
BK7 Optical Window FAQ
What is the function of a BK7 optical window?
A BK7 optical window transmits visible and near-infrared light while providing protection for internal optical components in imaging, laser and measurement systems.
Why is BK7 glass commonly used for optical windows?
BK7 provides excellent optical homogeneity, good transmission performance, low distortion and stable mechanical properties, making it suitable for a wide range of optical applications.
What coating options are available for BK7 optical windows?
BK7 optical windows can be manufactured with broadband AR coatings, V-coatings, multi-layer AR coatings and custom optical coatings for different wavelength requirements.
Can custom BK7 optical windows be manufactured?
Yes. Chenyu Optics provides customized BK7 optical windows with different sizes, thicknesses, surface quality, coatings and optical specifications according to system requirements.
What information should I provide for a quotation?
Please provide the BK7 or N-BK7 material grade, dimensions or diameter, thickness and tolerance, parallelism or wedge, surface figure, surface quality, clear aperture, bevel or chamfer, operating wavelength, coating and angle of incidence, quantity, drawing, inspection requirements and any packaging requirements.
How are BK7 optical windows inspected and packaged?
Inspection is arranged according to the agreed specification and may include dimensional measurement, visual surface inspection, interferometric surface-figure testing and spectral coating measurement. Windows are individually protected and packed to reduce surface contact, contamination and transport damage.
Related Products for BK7 Optical Window
Request A Quote For Custom BK7 Optical Windows
Send the material grade, dimensions, thickness and tolerance, parallelism or wedge, surface figure, surface quality, clear aperture, bevel or chamfer, operating wavelength, coating and angle of incidence, quantity, drawing, inspection requirements and any special packaging requirements.