Material: High grade BK7 (N-BK7) or UV grade fused silica (UVFS) glass
Large apex angle close to 180°
Widely used in interferometers, auto/cross-correlators, and GRENOUILLEs.
With a base of 1.0mm for apex angle > 160°.
With/without a base for apex angle =< 160°
Uncoated for standard products. AR coating available upon request.
| Model | Name | material | angle | coating | Price | Availability | Action |
| FBP1510G-160N | BK7 Fresnel biprism, base 15x10x0.0mm ( no base ), apex angle=160deg., polished and uncoated on three faces | N-BK7 | 160 deg | Uncoated | USD$179.00 | ||
| FBP2020G-160 | BK7 Fresnel biprism, base 20x20x1.0mm, apex angle=160deg., polished and uncoated on three faces | N-BK7 | 160 deg | Uncoated | USD$209.00 | Out Of Stock | |
| FBP5050G-160N | BK7 Fresnel biprism, base 50x50x0.0mm, apex angle=160deg., polished and uncoated on three faces | N-BK7 | 160 deg | Uncoated | Ask | Out Of Stock | |
| FBP2020G-170 | BK7 Fresnel biprism, base 20x20x1.0mm, apex angle=170deg., polished and uncoated on three faces | N-BK7 | 170 deg | Uncoated | USD$219.00 | Out Of Stock | |
| FBP5050G-170 | BK7 Fresnel biprism, base 50x50x1.0mm, apex angle=170deg., polished and uncoated on three faces | N-BK7 | 170 deg | Uncoated | Ask | Out Of Stock | |
| FBP2020G-175 | BK7 Fresnel biprism, base 20x20x1.0mm, apex angle=175deg., polished and uncoated on three faces | N-BK7 | 175 deg | Uncoated | USD$219.00 | Out Of Stock | |
| FBP2020G-177 | BK7 Fresnel biprism, base 20x20x1.0mm, apex angle=177deg., polished and uncoated on three faces | N-BK7 | 177 deg | Uncoated | USD$229.00 | Out Of Stock | |
| FBP2020G-179 | BK7 Fresnel biprism, base 20x20x1.0mm, apex angle=179deg., polished and uncoated on three faces | N-BK7 | 179 deg | Uncoated | USD$269.00 | ||
| FBP2020Q-150N | UVFS Fresnel biprism, base 20x20x1.0mm, apex angle=150deg., polished and uncoated on three faces | UVFS | 150 deg | Uncoated | USD$219.00 | Out Of Stock | |
| FBP2020Q-155 | UVFS Fresnel biprism, base 20x20x1.0mm, apex angle=155deg., polished and uncoated on three faces | UVFS | 155 deg | Uncoated | USD$219.00 | Out Of Stock | |
| FBP1515Q-160N | UVFS Fresnel biprism, base 15x15x0.0mm (no base), apex angle=160deg., polished and uncoated on three faces | UVFS | 160 deg | Uncoated | USD$209.00 | Out Of Stock | |
| FBP2020Q-160N | UVFS Fresnel biprism, base 20x20x0.0mm, apex angle=160deg., polished and uncoated on three faces | UVFS | 160 deg | Uncoated | Ask | Out Of Stock | |
| FBP2020Q-160 | UVFS Fresnel biprism, base 20x20x1.0mm, apex angle=160deg., polished and uncoated on three faces | UVFS | 160 deg | Uncoated | USD$219.00 | Out Of Stock | |
| FBP5050Q-160N | UVFS Fresnel biprism, base 50x50x0mm, apex angle=160deg., polished and uncoated on three faces | UVFS | 160 deg | Uncoated | USD$349.00 | ||
| FBP2020Q-170 | UVFS Fresnel biprism, base 20x20x1.0mm, apex angle=170deg., polished and uncoated on three faces | UVFS | 170 deg | Uncoated | USD$219.00 | Out Of Stock |
Basic Properties of BK7 and N-BK7 Glass:
|
BK7 |
N-BK7 (RoHS) | |
| Transparency Range | 360 - 2000 nm | 360 - 2500 nm |
| Density | 2.51 g/cm3 | 2.51 g/cm3 |
| Thermo-Optic Coefficients (dn/dT) |
2.3 x 10-6 /oC | 2.3 x 10-6 /oC |
| Optical Homogeneity | Δn < 10-6/cm | Δn < 10-6/cm |
| Knoop Hardness | 610 | 610 |
| Thermal Conductivity | 1.1 W/m/K | 1.1 W/m/K |
| Thermal Expansion Coefficients |
8 x 10-6/K |
7.1 x 10-6/K |
| Sellmeier Equations (λ in µm) |
n2=1+1.03961λ2/(λ2- 0.0060007 ) +0.23179λ2/(λ2-0.020018)+1.01047 λ2/(λ2-103.5600) | n2=1+1.03961λ2/(λ2- 0.0060007 ) +0.23179λ2/(λ2-0.020018)+1.01047 λ2/(λ2-103.5607) |
| Wavelength (nm) | Index of Refraction | |
| 400 | 1.5308 | 1.5308 |
| 532 | 1.5194 | 1.5194 |
| 588 | 1.5167 | 1.5167 |
| 632.8 | 1.5150 | 1.5150 |
| 800 | 1.5108 | 1.5108 |
| 1064 | 1.5066 | 1.5066 |
Transmission curve:
Basic Properties of Fused Silica Glass:
| Transparency Range: 185 - 2300 nm |
|
| Density: 2.2 g/cm3 | |
| Thermo-Optic Coefficients: dn/dT= 1.0 x 10-5 /oC |
|
| Optical Homogeneity: Δn < 10-6/cm | |
| Mohs Hardness: 7 | |
| Thermal Conductivity: 1.4 W/m/K | |
| Thermal Expansion Coefficient: | α = 0.54 x 10-6/K |
|
Sellmeier Equations: (λ in μm) : |
|
| Wavelength(nm) | Index of refraction |
| 1550 | 1.4440 |
| 1320 | 1.4466 |
| 1064 | 1.4496 |
| 800 | 1.4533 |
| 632.8 | 1.4570 |
| 532 | 1.4607 |
| 400 | 1.4701 |
| 355 | 1.4761 |
| 266 | 1.4997 |
| 213 | 1.5352 |
Fresnel Biprism Specifications
Dimension Tolerance:+/- 0.2 mm
Protective Bevel: ~ 0.2 mm for biprisms without a base
Flatness: λ/4 at 632.8 nm
Surface Quality: 20-10 scratch and dig
Clear Aperture: > 80%
