SELFOC®Plano-Convex (PC) Lens The SELFOC® Plano-Convex Lens features a curved surface on one end facet, designed to reduce spherical aberration in the lens. The result is an increased acceptance angle, smaller spot size as shown in the Figure to the right. The most common application is coupling from a light source, such as a laser diode or LED, into an optical fiber. There are three types of PC lens: PCW, PCH, and PCT, all with 1.8 mm diameter. The characteristics of PCW and PCH are listed in the Table below. PCT has higher coupling efficiency than PCW or PCH due to better control of higher order coefficients in the index distribution equation. There are two coupling schemes: the single lens system and the confocal (two-lens) system. The confocal system is used where it is necessary to include an additional optical component (e.g. filter, isolator) between the light source and the fiber. Proper handling and storage of lenses. Table 1 Optical Design Parameters for PCW and PCH Standard Wavelength 830 nm 1300 nm 1560 nm   Pitch NA On Axis 2q (deg) No ÖA Z (mm) No ÖA Z (mm) No ÖA Z (mm) PCW 0.25 0.46 55 1.599 0.332 4.73 1.592 0.327 4.80 1.590 0.326 4.81 PCH 0.22 0.60 74 1.646 0.423 3.27 1.636 0.418 3.30 1.634 0.417 3.30 0.20 2.97 3.01 3.01 PCT   0.60 74       1.636 0.392 3.26 1.634 0.391 3.26 2.83 2.83 * Radius of Curvature(R): For PCW and PCH, R = 2.0 +/- 0.1 mm. * For PCT, lens is specified by Z (length) value rather than the pitch; R may vary from 1 to 3 mm as determined by NSG based on index distribution of each lot.   Ordering Information Example: Type Diameter Pitch Wavelength AR Coating; Metallization PCH 180 022 130 A2 M AR Coating: A2, C1, etc., NC = Non-coated When AR coating is specified for one side only, e.g., A1, D1, etc., the coating is applied to the convex side unless otherwise specified by the customer. Metallization: M = Metallization, 0 = Non-metallized Part Numbers for PCT: PCT 180 326 130 A2M Z PCT 180 326 155 A2M Z PCT 180 283 130 A2M Z PCT 180 283 155 A2M Z