Low Reflectance and Reflowable Thermoplastic Optical Lens Without AR Coating

Plastic lenses are utilized for optical communication devices such as AOC (Active Optical Cable), optical transceivers and optical connectors in order to improve optical coupling efficiency. In order to reduce the loss of the optical communication device one must also, reduce the Fresnel loss due to the refractive index of the resin; the typical solution is, use of an Anti-reflection (AR) coating. Although it is possible to greatly lower the reflectance at the end face of the lens by this AR coat, the cost of the device is increased. To solve this problem we propose, reduction of reflectance in the near infrared wavelength band without AR coating by transferring the nanoscale concavo-convex structure to the lens surface through injection molding alone. Furthermore, we confirmed good reflow resistance of nanoscale concavo-convex structure used reflowable thermoplastic resin.