High Efficiency Polarizing Beamsplitter- 10% Improvement
By admin · Optics PDFs · 27/03/14
The Moxtek® wire grid polarizer technology offers a reliable, highly durable solution to high quality LCoS display technology with a perfect polarization match to the LC imager. Recent improvements in the polarizing beam splitter (PBS) technology enable a 10% improvement in efficiency.
Table 1 Comparison of Technologies
IntroductionThis technical brief compares imaging needs and how Moxtek is improving its products. It explains how competing technologies in LCoS projectors compare in terms of brightness, performance, durability and reliability.
PBS EfficiencyEfficiency (Tp*Rs) for a polarizing beamsplitter is a measure of how perfectly a polarizer converts randomly polarized light into (reflected) s and (transmitted) p polarized light. If all of the light is converted, then the beamsplitter would be 100% efficient. In reality, some of the light is absorbed, some ‘s’ is transmitted and some ‘p’ is reflected, reducing the efficiency. The Moxtek standard PBS is typically 81% efficient at 550nm wavelength. Recently, with improved manufacturing techniques and new wire grid technology, this efficiency has been dramatically improved. Figure 1 shows the improvement in efficiency for the Moxtek High Efficiency PBS (HEPBS) versus standard PBS. This represents a 10% improvement.
|Element||ProFlux Wire Grid||Dichroic Polarizer||MacNeille Polarizer|
|Polarizing Mechanism||Polarizer using a nano-|
structured thin film
|Resonant absorption in thick stretched film||Reflects s-polarization and transmits p-polarization|
|Significance||A perfect polarization match to the LC imager, even skew rays can align to the LC. PBS: f/1.5 and below.|
PPL: f/1.0 and below.
|Thick polarizing film results in beam depolarization||Polarization direction depends on incoming ray: skew rays are not aligned to LC|
|Contrast||Excellent brightness, contrast, and on-screen|
|Reduced contrast and uniformity||Reduced contrast and uniformity|
|Durability||Made from all inorganic|
materials for high durability
|Polymer film degrades over time and in high flux conditions||Requires polymer waveplate for correct polarization|