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BVO NIR 4ST
BVO NIR 4ST Linear Polarizer
Active Range: 525 nm – 1,000 nm | Supreme Long VIS + Broadband NIR | Contact BVO for Availability
37,349:1 VIS Contrast
525–1000 nm
White LED + NIR sensor coverage
Absorptive
Hybrid Dyestuff
BVO NIR 4ST is a hybrid dyestuff NIR linear polarizer engineered for supreme performance across the long visible and full NIR band — 525 nm to 1000 nm — in a single optical element. Where other NIR family members trade Tp for contrast or coverage, NIR 4ST maintains exceptional single-pass transmission (72.3% average) with strong contrast across the entire 525–1000 nm bandwidth. The hybrid dyestuff construction delivers 37,342:1 average contrast in the long visible band (525–700 nm) and 17,733:1 across the NIR (700–1000 nm), while keeping Tp remarkably flat — just 69–76% from 525 nm all the way to 1000 nm. Contact Bolder Vision Optik directly for availability and pricing — this product is not listed on the main website.
Availability note: BVO NIR 4ST is handled on a case-by-case basis. Contact BVO directly at
[email protected] or
303.440.3327 to discuss your application requirements.
72.3%
Avg Tp — 525–1000 nm
37,342:1
Avg Contrast Long VIS (525–700 nm)
17,733:1
Avg Contrast NIR (700–1000 nm)
BVO NIR 4ST Linear Polarizer — Transmission Performance
Input Light: Plane Polarized | Measured Range: 400–1100 nm | Tc below 0.01% from 566–808 nm | Tc minimum 0.0004% at 692 nm
Key Features
- Supreme long VIS + broadband NIR performance — active range 525 nm to 1000 nm
- 72.3% average single-pass Tp across 525–1000 nm — exceptionally flat across 475 nm bandwidth
- 37,342:1 average contrast in long VIS band (525–700 nm)
- 17,733:1 average contrast across NIR (700–1000 nm)
- Tp flatness: 69–76% from 525 nm to 1000 nm — minimal variation across the full active range
- Hybrid dyestuff construction — hybrid dyestuff construction tuned for broad long VIS + NIR coverage
- Not active below 525 nm — for 400 nm coverage see NIR Ultra or NIR HD
- Absorptive, non-reflective — no back-reflection artifacts
- BBAR anti-reflection coated BK-7 glass components available
- PSA conversion available for direct lamination
- Custom geometry — .dxf routing or laser cutting to 10–25 micron tolerances
- Contact BVO directly for availability and pricing
Performance
NIR 4ST is engineered for applications requiring a single polarizer with excellent performance across the full long visible and NIR band — 525 nm to 1000 nm. The defining characteristic is Tp flatness: single-pass transmission stays between 69% and 76% across the entire 475 nm active bandwidth, with remarkably little variation. Most polarizers sacrifice Tp at one end of the band to achieve contrast at the other — NIR 4ST maintains both simultaneously across a wider range than any other product in the BVO NIR family.
NIR 4ST is not active below 525 nm — the hybrid dyestuff system is tuned for long VIS and NIR performance, not blue/UV. Above 525 nm contrast rises sharply, reaching 37,342:1 average across the long visible band (525–700 nm) and maintaining 17,733:1 average across the NIR (700–1000 nm). This combination of high Tp and broad contrast bandwidth is the differentiator from other family members, which achieve higher peak contrast in narrower bands but at lower Tp or less consistent performance across the full range.
Key Wavelength Data — Active Range 525–1000 nm
| Wavelength | Tp (%) | Tc (%) | Contrast | Note |
|---|
| 400–524 nm | — | — | — | Below active range — not specified |
| 525 nm | 72.2% | 0.133% | 545:1 | Active range start — contrast rising |
| 550 nm | 72.3% | 0.027% | 2,647:1 | Long VIS — contrast climbing |
| 600 nm | 73.2% | 0.004% | 17,418:1 | Long VIS — excellent contrast |
| 650 nm | 73.2% | 0.002% | 48,820:1 | Long VIS — peak contrast zone |
| 700 nm | 74.4% | 0.001% | 106,347:1 | Long VIS/NIR transition — peak contrast |
| 750 nm | 74.2% | 0.003% | 29,676:1 | NIR — excellent contrast + high Tp |
| 800 nm | 71.5% | 0.009% | 8,316:1 | NIR — strong contrast + high Tp |
| 850 nm | 69.4% | 0.013% | 5,426:1 | NIR — good contrast + high Tp |
| 900 nm | 69.4% | 0.013% | 5,378:1 | NIR — good contrast + high Tp |
| 940 nm | 71.1% | 0.017% | 4,185:1 | NIR — good contrast + high Tp |
| 1000 nm | 76.3% | 0.088% | 871:1 | Upper active range — Tp rising, contrast falling |
Standard Specifications
| Parameter | Value |
|---|
| Optimized Range | 525 nm – 1,000 nm |
| Measured Range | 400 nm – 1,100 nm |
| Contrast Ratio VIS | 37,349:1 average (525–700 nm) |
| Contrast Ratio NIR | 17,373:1 average (700–1000 nm); 4,607:1 avg (800–1000 nm) |
| Tc Minimum | 0.0004% at 692 nm |
| Tc < 0.01% Range | 566 nm – 808 nm |
| Construction | Hybrid dyestuff absorptive system |
| Film Cut Tolerances | ±50 microns standard; 10–25 microns precision |
| Temperature Range | −20°C to 70°C |
| Substrate | Plastic Cellulose Triacetate, dichroic hybrid dyestuff |
| Surface Quality Film | 80/50 Scratch-Dig |
| Surface Quality Glass | 40/20 Scratch-Dig |
| Glass Component OD | 25.4 mm OD ± 0.20 mm |
| Wavefront Distortion | λ/2 measured at 632 nm |
| Beam Deviation | 2 arc minutes |
| Anti-Reflective Coatings | 400–900 nm or 700–1100 nm BBAR |
| Availability | Contact BVO directly — not listed on website |
Applications
Broadband Long VIS + NIR Polarimetry
Stokes polarimetry and polarization measurement systems spanning 525–1000 nm. Single element with consistently high Tp and contrast across the full band.
Hyperspectral / Multispectral Imaging
Hyperspectral cameras spanning the long VIS and NIR. Flat Tp (69–76%) across 525–1000 nm avoids the spectral artifacts introduced by polarizers with uneven Tp profiles.
NIR Laser Polarization (650–1000 nm)
High Tp diode laser polarizer across the red/NIR band. Strong contrast at key diode wavelengths — 700, 750, 808, 830, 850, 940 nm.
Machine Vision Long VIS + NIR
Industrial imaging systems operating from 525 nm through the NIR. High Tp and broad contrast in a single absorptive element — no back-reflection.
Defense / Airborne NIR Imaging
Airborne and ground-based imaging systems covering the long visible and NIR band. Absorptive construction eliminates back-reflection into sensitive detector arrays.
Fluorescence / Emission Imaging
Long VIS and NIR fluorescence polarization imaging. High contrast from 525 nm eliminates excitation background while maintaining high collection efficiency (Tp).
BVO NIR Family — Where 4ST Fits
| Property | NIR 4ST | NIR DS2 | NIR Ultra | NIR HD |
|---|
| VIS contrast avg (525–700 nm) |
21,877:1 |
15,630:1 |
20,000:1 |
20,000:1 |
| NIR contrast avg (700–1000 nm) |
17,373:1 |
30,629:1 (800–1000) |
7,000:1 |
5,000:1 |
| Tc minimum |
0.0004% @ 692 nm |
0.001% @ 900 nm |
0.002% @ 630 nm |
0.002% @ 600 nm |
| Tc < 0.01% range |
566–808 nm (242 nm span) |
560–1065 nm |
510–870 nm |
530–700 nm |
| Construction |
Hybrid dyestuff |
Dyestuff NIR-optimized |
Hybrid dichroic |
High durability dyestuff |
| Availability |
Contact BVO direct |
Standard catalog |
Standard catalog |
Standard catalog |
Contact Bolder Vision Optik
