In an f-theta scanning system, spot size and input beam diameter are inversely related: double the collimated beam diameter at the lens, and the focused spot diameter halves. That single relationship is the reason a beam expander sits between almost every laser and every galvanometer…

F-theta distortion and field curvature are both field-dependent errors in a laser scan lens, but they fail in completely different ways. F-theta distortion is a position error: the focused spot lands somewhere other than where the scan angle says it should, while staying sharp. Field…

Searching for a custom optics manufacturer in China usually means the optical function is already known, a drawing exists, or a prototype needs to be converted into a repeatable production component. The difficult part is not finding a company that can make a lens, filter,…

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 ray normal and a uniformly filled pupil, the mean shift equals half the marginal-ray shift. The same cone produces far…

The central difference in an aspheric lens vs spherical lens comparison is surface geometry. A spherical surface has a constant radius of curvature, while an aspheric surface deliberately changes curvature from its optical axis toward its edge. That extra design freedom can reduce spherical aberration…

The practical difference in an achromatic lens vs singlet lens comparison is wavelength control. A singlet uses one optical element and is usually adequate for monochromatic light, modest numerical aperture, or applications with relaxed imaging requirements. An achromatic lens normally combines two elements with different…