Insights
How to Specify an Optical Window for an RFQ
An optical window may look mechanically simple, but a useful quotation depends on the complete optical, mechanical and environmental specification. If a buyer sends only diameter and thickness, suppliers may assume different materials, tolerances or coating targets and return quotations that cannot be compared.
Start with the application and spectral band
Describe what the window protects and which wavelengths must pass through it. Imaging, laser, sensing, vacuum, pressure, outdoor and thermal applications can lead to different substrate, coating and mounting decisions. State the operating band, angle of incidence and whether transmission, reflection, wavefront or laser-damage performance is critical.
Define the geometry and usable aperture
- Outside dimensions, thickness and dimensional tolerances
- Round, rectangular or custom outline
- Clear aperture and any masked or mounted area
- Chamfer, bevel, edge finish and orientation marks
- Parallel surfaces or a controlled wedge angle
A drawing should identify which surfaces are optical and which dimensions interface with the housing. For thin or large windows, the mounting method and pressure load can be as important as the nominal dimensions.
Separate surface quality from transmitted performance
Surface quality addresses visible defects such as scratches and digs, while flatness and transmitted wavefront describe different aspects of optical performance. Do not copy a tight value from another design unless the system needs it. Over-specification raises manufacturing and inspection cost without necessarily improving the final instrument.
Make the coating measurable
State the wavelength range, target transmission or reflection, angle of incidence, polarization if relevant, and environmental durability requirement. “AR coating” alone is not enough because a coating optimized for one band or angle may perform differently in another system.
Ask for the right inspection evidence
Identify which parameters require a measurement report, certificate of conformity or coating curve, and whether the report is required for the sample, each batch or every part. Agree on sampling, cosmetic inspection conditions, packaging and labeling before production.
Optical-window RFQ checklist
Include the application, spectral band, substrate or acceptable alternatives, drawing, clear aperture, surface quality, flatness or wavefront requirement, parallelism or wedge, coating target, environmental tests, quantity and required documents.
Review our custom optical windows page or email sales@tuolango.com with the drawing and application for a project-specific review.