|Materials||N-BK7||Lens Type||Ball lens|
|Diameters(mm)||4.0||Diameter Tolerance (μm)||+/-2.5|
|Design Wavlength(nm)||587.6||EFL (Effective Focal Length) (mm)||2.93|
|BFL (Back Focal Length) (mm)||0.93||Sphericity (μm)||2.0|
|Surface quality||40/20 S/D||Irregularity(@633nm)||λ/4|
|Coating||None||Wavelength Range (nm)||350-2200|
Ball lenses belong to a special form of biconvex lenses which have the geometry of a ball(sphere). They are manufactured from a single material, usually an optical glass with good transparency in the wavelength region of interest. The typical applications of ball lenses include focusing light in the field of fibers(e.g. laser to fiber coupling ,fiber to fiber coupling), emitters and detectors , majorly to collimate light depending on geometries of the input light source. Also they could be ball pre-forms of aspheric lenses where they are purposefully deformed in order to prevent spherical aberrations.
Half-Ball lenses are variants of ball lenses, obtained by simply cutting the ball lenses in half.Due to ease of mounting brought by the one flat surface,they are ideal for applications where more compact designs are required , such as fiber communication, endoscopy, microscopy, optical pick-up devices, and laser measurement systems.
Hangzhou Shalom EO provides both stocked and custom ball lenses and half ball lenses made from N-BK7, UV fused silica, Sapphire and high index optical glass materials.The specification of custom ball and half ball lenses could be varied upon your request.
There are some typical features of N-BK7:
N-BK7 is a very pure and Standard glass types used to produce high-quality optics, mainly for the visible spectrum. It is one of the most frequently used optical glass,This relatively hard and stable borosilicate crown material possesses high purity and quality with very few inclusions and is almost free of bubbles.The high quality of material of N-BK7 glass is a primary technical reason why it is the optimized choice for optical applications. Other features of N-BK7 which are advantageous for optical usage include smooth transmission and low absorption in the entire visible wavelength range.It is worth noting that under normal conditions N-BK7 has a more instable polishing and is softer than FS, and additionally N-BK7 has higher losses through higher absorption and scattering and therefore are relatively less suitable for high power applications.