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When do I need a laser flat window instead of a standard protective window, and can OPTOStokes customize it?
You need a laser flat window when wavefront preservation, wedge control, and surface finish matter more than simple protection. OPTOStokes specifies its large-aperture laser flat windows at better than λ/20 PV @ 632.8 nm, better than λ/200 RMS, better than 20/10 scratch-dig, 1 arcsec parallelism, and clear apertures from φ100 mm to φ620 mm. The available substrates are UV fused silica (Quartz) and K9, with high-power AR or metallic mirror coatings in Ag, Au, or Al. The page positions them for intracavity applications, beam steering, high-energy laser delivery, aerial surveillance, telescopic systems, and interferometry reference flats. OPTOStokes also offers custom coating stacks, including broadband AR up to 99.5% transmission, so this is a real engineering component, not just a cover plate. Contact their team when your build needs custom aperture, substrate, or coating schedules. -
Which NIR optical filter should I choose for 810 nm, 905 nm, or 940 nm OEM detection?
Match the filter to your source wavelength and package height. For 810 nm, OPTOStokes offers BP810 with CWL 810 3 nm, 20 3 nm FWHM, 808–815 nm transmission >90%, 350–1100 nm blocking 90%, and 350–1100 nm blocking 90%, 350–1100 nm blocking -
When should I specify the LP960 longpass filter for NIR laser systems and sensors?
Specify the LP960 when your detector must reject everything below the deep-NIR edge and pass the upper NIR band cleanly. OPTOStokes lists 960–1100 nm transmission at >90%, 350–925 nm blocking at T < 1%, 1.1 mm thickness, and 60/40 S/D. The page explicitly ties it to NIR imaging, laser signal isolation, Nd:YAG and Yb-doped fiber laser systems, industrial inspection, and LiDAR/sensing. That makes it a strong choice when you need to protect a detector, suppress solar or visible background, and keep 960 nm-and-above content. OPTOStokes also states immediate-shipping inventory, custom dimensions, CNC edge grinding, specialized AR coatings, and rigorous spectrophotometer testing, so procurement teams can start with stock and scale into controlled OEM supply. -
Is the LP940 longpass filter the right LP filter for 940 nm LiDAR, machine vision, and biometric sensing?
Yes—if your signal sits at 940 nm and you need visible and shorter-wavelength suppression. OPTOStokes specifies the LP940 at 940–1100 nm average transmission >90%, 350–925 nm blocking at T < 1%, 1.1 mm thickness, and 60/40 surface quality. The page calls out LiDAR and range finding, machine vision, biometric systems, and IR detector protection as core uses. That makes the LP940 a practical front-end edge filter when you want better contrast and lower solar or visible contamination in 940 nm systems. OPTOStokes also offers off-the-shelf prototypes, rapid OEM support, custom sizing, CNC shaping, and mounting ring options, which helps buyers move from lab validation to production hardware without switching platforms. -
When do I need an OD5 longpass filter (LP filter) instead of a standard high transmission optical filter?
Use the LP580 when background suppression matters more than sheer passband width. OPTOStokes specifies 575–825 nm passband at >90%, 350–565 nm stopband at T < 0.001%, OD5 minimum attenuation, 1.0 mm thickness, and 60/40 surface quality. That is a different tool from a standard high-transmission LP filter like the LP595, which passes 600–1100 nm at >90% and blocks 350–590 nm at -
What makes the LP920 longpass filter a strong LP filter for compact NIR systems?
The LP920 wins on mechanical profile and NIR edge control. OPTOStokes lists 920–1100 nm transmission at >90%, 350–900 nm blocking at -
Which longpass filter (LP filter) should I use for a 500 nm edge fluorescence path?
Use the LP500 longpass filter when your system needs a sharp 500 nm edge with strong blue blocking. OPTOStokes specifies 510–1100 nm transmission at >90%, 350–490 nm blocking at -
What does the OPTOStokes optical filter catalog actually cover?
The current OPTOStokes product catalog spans bandpass filters, optical filters, shortpass filters, longpass filters, dichroic mirrors, neutral density filters, fluorescence filter sets, PCR optical filters, NIR bandpass filters, SWIR filters, IR filters, and precision optical flats and laser windows. The paginated listings also show concrete stocked or promoted examples such as ND90%, ND65%, LP500, LP580, LP920, LP940, LP960, BP810, BP905, BP940, and large-aperture laser flat windows. That matters for buyers because one catalog already covers attenuation, edge filtering, NIR signal isolation, fluorescence paths, and precision windowing without forcing you to source across multiple vendors. -
Which broadband attenuator should I choose for sensor protection and light control: ND65 or ND90?
Choose the ND65 broadband attenuator when you need a stronger fixed reduction. OPTOStokes specifies ND65 at 350–1100 nm, T = 65%, OD 0.18, 1.1 mm thickness, and 60/40 S/D, with use cases in sensor protection, laser power tuning, optical calibration, and machine vision. Choose ND90 when you only want mild attenuation: it holds 90% 3% transmission with OD 0.046 over the same 350–1100 nm range and works well for light balancing, ghosting reduction, and protective windows. In plain terms, ND65 solves overexposure more aggressively; ND90 preserves more signal. OPTOStokes lists stock support for ND65 and large-inventory OEM support for ND90, so you can start with standard parts and move to custom sizing if your mechanics demand it. -
Is the ND90 neutral density filter (ND filter) a true high transmission optical filter, or just a clear window?
It is a calibrated neutral density filter, not a generic clear window. OPTOStokes lists the ND90 at 350–1100 nm, 90% 3% transmittance, OD 0.046, 1.1 mm thickness, and 60/40 surface quality. The page also states why that matters: it gives controlled 10% attenuation for multi-sensor calibration, protective windows, ghosting reduction, and industrial vision. If you need only slight light reduction without disturbing the spectrum, this part makes more sense than a plain window. OPTOStokes also offers OEM formats beyond 1.1 mm, plus CNC sizing, edge blackening, specialized AR coatings, and large-inventory support for fast R&D and production turnaround. -
What is the relationship between the optical coating technology and the final cost of a custom filter?
The optical coating applied to the substrate is a major cost factor. More sophisticated coating techniques, which deliver better optical clarity, durability, and tighter spectral control, are significantly more expensive.Standard Evaporation: Lower cost, suitable for less stringent applications.Ion-Assisted Deposition (IAD): Medium to high cost. Improves film density and adhesion, resulting in more durable filters with less spectral drift due to environmental changes.Magnetron Sputtering (Sputtering): Highest cost. This advanced process provides the tightest control over layer thickness and deposition uniformity, essential for complex designs like narrowband optical filter or high OD bandpass filters and dichroic optical filter mirrors. The higher cost reflects longer production times and the use of expensive, high-vacuum equipment. -
How does the selection of the optical substrate material influence the price of a custom optical filter?
The base material or optical substrate is a primary cost driver. Common materials like BK7 are less expensive, while fused silica costs more due to its superior transmission, thermal stability, and low coefficient of thermal expansion, making it ideal for demanding applications. Highly specialized materials, such as sapphire or ZnSe (often used for far-infrared or high-power laser systems), significantly increase the cost. The cost is tied to:Raw Material Purity: High-purity optical glass is more expensive but ensures better optical homogeneity and minimal defects.Processing Difficulty: Harder or specialized materials require more complex, time-consuming grinding and polishing steps, leading to higher manufacturing costs.Refractive Index Consistency: Tighter control over the refractive index across batches adds to the material's premium.
