understanding ball and half ball lens use

ball lens & Half Ball lens

Ball lens is spherically shaped, usually keeps a constant refractive index, and is made from synthetic sapphire, ruby, glass, ceramic, cubic zirconia, spinel, low tg glass or other transparent optical substrates. Transmitted light changes direction at the curved boundaries, traversing the interior in straight lines. The focal length, measured from the centre of the lens, and back focal length, measured from the surface of the lens. The focal length is dependent upon both the refractive index of the glass and the lens diameter. Placing a point source at the focal point of the lens results in collimated light.

Ball lens is glass spheres commonly used to improve signal coupling between fibers, emitters, and detectors. ball lens also used in endoscopy, bar code scanning, ball pre-forms for aspheric lenses, and sensor applications. Ball Lens are manufactured from a single substrate of glass and can focus or collimate light, depending upon the geometry of the input source. Half ball lens is also common and can be interchanged with full ball lens if the physical constraints of an application require a more compact design.

AR-coated ball lenses is completely covered, and have losses less than 0.01dB (99.75% T) per surface, over broad wavelength ranges. ball lenses is much less expensive compare to GRIN lenses, made from a wide range of substrate with consequent diversity of refractive index, and help to reduce package size. Finally, alignment labour is affectedly reduced when using these lenses, as no rotational orientation is required.