Scratch-Dig vs Surface Roughness
Scratch-dig limits discrete local defects; surface roughness is the RMS height of fine texture across the whole surface. The MIL-PRF-13830B scratch number is a visibility…
Read articleGIAI Photonics
Optical Engineering
Here we provide articles about popular science and applications of filters, lenses, prisms, reflectors, ND mirrors and other optical components. You are welcome to read! optical engineering articles, optical engineering guides, optical components, optical design, optics technology, photonics engineering
Clear Aperture vs Optic Diameter
Optic diameter is the physical outside diameter of a circular optical component. Clear aperture is the region of that optic over which specified optical performance…
Read article
Aspheric Lens vs Plano-Convex Lens
A collimated N-BK7 plano-convex lens with f = 50 mm reaches the 0.07 λ RMS diffraction limit at f/6.4 (computed, 587.6 nm). Face the curved…
Read article
Cone Half Angle Effect on Interference Filters
A cone half angle shifts an interference filter's spectrum toward shorter wavelengths and softens its edges; a pure tilt only shifts it. With the chief…
Read article
What Makes Optical Coating Expensive?
Two optical components can look almost identical, use the same substrate material, and have similar dimensions—yet their coating costs may be very different. The reason…
Read article
What Is an F-Theta Scan Lens and How Does It Work?
The topic is suitable as a foundational definition page. GIAI already has more specific content covering 1064 nm F-theta lenses, field-size calculation, standard vs. telecentric…
Read article
Beam Expander: How It Works, Magnification & Trade-offs
A beam expander is an afocal telescope that scales a collimated beam diameter by M. Far-field divergence scales by 1/M; the diameter-angle product stays fixed…
Read article
How S and P Polarization Affect Beamsplitter Selection
A beamsplitter does not treat s- and p-polarized light the same way. At any angle other than normal incidence, the reflectance of a surface or…
Read article
What Is Extinction Ratio in a Polarizer?
Extinction ratio is the ratio between the transmittance a polarizer gives to the polarization state it passes and the transmittance it gives to the orthogonal…
Read article
Cube Beamsplitter vs Plate Beamsplitter
Cube Beamsplitter vs Plate Beamsplitter: Which Design Is Better for Your Optical System? Neither a cube beamsplitter nor a plate beamsplitter is universally better. A…
Read article
Sapphire vs Fused Silica Optical Windows: How to Choose
Choose fused silica when the window must work in the deep UV, must not disturb polarization or wavefront, or must survive fast thermal transients; choose…
Read article
Dielectric Coating vs Metallic Coating
When specifying a mirror, beamsplitter, filter, or other coated optical component, choosing between a dielectric coating and a metallic coating is not simply a question…
Read article