Waveplates are made from materials which exhibit birefringence. The velocities of the extraordinary and ordinary rays through the birefringent material vary inversely with their refractive indices. This difference in velocities gives rise to a phase difference when the two beams recombine. In the case of an incident linearly polarized beam, this is given by α=2πd(ne-no)/λ, where is α phase difference; d is thickness of waveplate; ne, no are refractive indices of extraordinary and ordinary rays respectively; λ is wavelength. At any specific wavelength, the phase difference is governed by the thickness of the retarder.
Casix waveplates are widely used in the synthesis and analysis of light in various states of polarization. The wavelengths within the range of 240nm~2100nm are all available at CASIX.
Low Order Waveplates
• Thickness: 0.2-0.5mm
• High Damage Threshold
• Better Temperature Bandwidth
• Low Cost
Capability:
Attribute | Commercial | High Precision |
Material | Crystal Quartz, MgF2 | Crystal Quartz, MgF2 |
Dimension Tolerance | +0.0/-0.13mm | ±0.02mm |
Wavefront Distortion | λ/8@632.8nm | λ/20@632.8nm |
Retardation Tolerance | λ/120 measured at 632.8nm | λ/300 measured at 632.8nm |
Wavelength Range | 240~2100nm | 240~2100nm |
Parallelism | 3 arc seconds | 0.6 arc seconds |
Surface Quality(Scratch-Dig) | 20-10 | 10-5 |
AR/AR Coating | R<0.2% at central wavelength | R<0.1% at central wavelength |
Theoretical Retardance Curve
Zero-Order Waveplates
Cemented & Optically Contacted Zero-Order Waveplates
• Double Plates
• Broad Spectral Bandwidth
• Wide Temperature Bandwidth
• AR Coated
Capability:
Attribute | Commercial | High Precision |
Material | Crystal Quartz | Crystal Quartz |
Dimension Tolerance | +0.0/-0.2mm | ±0.05mm |
Wavefront Distortion | λ/4@632.8nm | λ/10@632.8nm |
Retardation Tolerance | λ/120 measured at 632.8nm | λ/300 measured at 632.8nm |
Wavelength Range | 400~2100nm | 240~2100nm |
Parallelism (Single Plate) | 3 arc seconds | 0.6 arc seconds |
Surface Quality(Scratch-Dig) | 20-10 | 10-5 |
AR/AR Coating | R<0.2% at central wavelength | R<0.1% at central wavelength |
Air-spaced Zero Order Waveplates
• Double Retardation Plates
• Wide Temperature Bandwidth
• Broad Spectral Bandwidth
• High Damage Threshold
• AR Coated and Mounted
Capability:
Attribute | Commercial | High Precision |
Material | Crystal Quartz | Crystal Quartz |
Dimension Tolerance | +0.0/-0.2mm | ±0.05mm |
Wavefront Distortion | λ/4@632.8nm | λ/10@632.8nm |
Retardation Tolerance | λ/120 measured at 632.8nm | λ/300 measured at 632.8nm |
Wavelength Range | 240~2100nm | 240~2100nm |
Parallelism (Single Quartz Plate) | 3 arc seconds | 0.5 arc seconds |
Surface Quality(Scratch-Dig) | 20-10 | 10-5 |
AR/AR Coating | R<0.2% at central wavelength | R<0.1% at central wavelength |
True Zero-Order Waveplates
Capability:
Attribute | Commercial | High Precision |
Material | Crystal Quartz,N-BK7 | Crystal Quartz,N-BK7 |
Dimension Tolerance | +0.0/-0.13mm | ±0.02mm |
Wavefront Distortion | λ/8@632.8nm | λ/20@632.8nm |
Retardation Tolerance | λ/120 measured at 632.8nm | λ/300 measured at 632.8nm |
Wavelength Range | 400~2100nm | 240~2100nm |
Parallelism | 3 arc seconds | 1 arc seconds |
Surface Quality(Scratch-Dig) | 20-10 | 10-5 |
AR/AR Coating | R<0.2% at central wavelength | R<0.1% at central wavelength |
Cemented True Zero-Order Waveplates
• Broad Spectral Bandwidth
• Wide Temperature Bandwidth
• Wide Angle Bandwidth
• Cemented by Epoxy
Single Plate True Zero-Order Waveplates
• Broad Spectral Bandwidth
• Wide Temperature Bandwidth
• Wide Angle Bandwidth
• High Damage Threshold
• Standard Wavelength: 1310nm, 1550nm
• λ/2 Waveplate
• Thickness Down to 0.028mm
Achromatic Waveplates
Achromatic waveplates are similar to zero-order except that the two plates are made of different materials, such as crystal quartz and magnesium fluoride.Since the dispersion of birefringence can be different for two materials, it is possible to specify the retardation value at a wavelength range. Hence, the retardation of the resulting waveplate can be made to low sensitivity to wavelength change.。
Based on the contact methods of two plates, achromatic waveplates are classified into two types: air-spaced and cemented.
Capability:
Attribute | Commercial | High Precision |
Substrate Material | Crystal Quartz and MgF2 | Crystal Quartz and MgF2 |
Dimension Tolerance | +0.0/-0.2mm | ±0.05mm |
Wavefront Distortion | λ/4@632.8nm | λ/8@632.8nm |
Retardation Tolerance | λ/50@700nm~1000nm (NIR) | λ/100@700nm~1000nm (NIR) |
Wavelength Range | 400~2100nm | 400~2100nm |
Parallelism (Single Plate) | 3 arc seconds | 1 arc seconds |
Surface Quality (Scratch-Dig) | 40-20 | 10-5 |
Standard Wavelength | VIS:465nm~610nm NIR:700nm~1000nm IR:1200nm~1650nm | VIS:465nm~610nm NIR:700nm~1000nm IR:1200nm~1650nm |