unique properties of Bessel beams allow for axicon applications in a range of fields. Axicons can aid improvements in medical applications such as laser corneal surgery, in which the ring-shaped beam provides increased capability in smoothing and vaporizing the corneal tissue. With the use of a negative and positive axicon, ring diameter can be adjusted to fit the patient's and surgeon's needs by manipulating the distance between the two axicons. Product Description We provide all kinds of customized optical lens which according to your drawings, sample products or detailed requirements. Any inquiry please feel free to contact us, thanks! We can provide virtually any size, shape and quality required by the customer. The range covers more than 60 types including the following types in the visible wavelength range from 200 nm upwards: Band pass filters, which allow required ranges to pass through selectively Long pass filters, which block unwanted shorter wave ranges Short pass filters, which block unwanted longer wave ranges Neutral density filters, which have a virtually constant transparency especially in the visible range Conversion filters, which due to their spectral range increase or reduce the colour temperature of radiation sources Materials Basic glass Ionically coloured glass Colloidally coloured glass Forms of Supply for optical Glass Filters Polished filter: Filters are available as polished plates or round discs with processed edges. Upon request, they are available thermally strengthened and/ or with protective/ antireflective coating Filter glass prepared: - With processessed edges Rectangular plates and round discs with matt surfaces and processed edges - Edges not processed Rectangular plates and round discs with matt surfaces and edges not processed. Standard formats with non-processed edges: Plate sizes 165 x 165 + 3-0 mm Plate thickness 3.5 mm +/- 0.5 mm and 4.5 mm +/- 0.5 mm Specifications Dimensions: from 1 mm - 480 mm Minimum thickness 0.1 mm Tolerances Up to 0.001 mm Surface quality Up to P 4 in compl. With DIN IS0 100110 Upon request, we can produce any size and thickness required within the framework of the maximum size permitted by the type of glass required. Applications Optical glass filters are used in a host of different applications. Optical glass filters are significant components in industrial measurement, control and regulation technology through analytical measuring methods in production, research and development all the way to environment protection and medicine with which to permit or block the transmission of specific spectral ranges. Filter Glass Types UG Black and blue glass which permits the transmission of UV light BG Blue, blue-green and bandglass VG Green glass GG Yellow glass which permits IR light transmission OG Orange glass which permits IR light transmission RG Red and black glass which permits IR light transmission NG Neutral glass with virtually constant radiation weakening in the visible range N-WG Colourless glass with different cut-off positions in the UV range and which allows IR and visible light transmission KG Virtually colourless glass with high transmission of visible light and absorption of radiation in the IR range FG Blue and brown coloured glass (conversion glass) Applications: 1 . Correcting Astigmatism One of the main applications of cylindrical lenses is in ophthalmology, specifically, to correct astigmatic vision. When a person presents astigmatic vision, it is usually the result of a corneal deformation. An astigmatic cornea will have different focal points at different axes. It is then possible to use a cylindrical lens to change the focal point of one of the axes to overlap the second one. 2 . Laser Line Scanni