title: Design and Fabrication of a Hybrid Diffractive Optical Device for Multiple-Line Generation over a Wide Angle.
abstract: A new hybrid optical device that is capable of splitting a monochromatic laser beam into an arbitrary number of lines over a wide angle is presented. It consists of a binary surface-relief computer-generated phase hologram and a continuous parabolic surface-relief grating. In this device the phase hologram serves to generate three small, parallel lines while the continuous parabolic surface-relief phase grating acts as an array of diverging parabolic lenses to widen these lines. The binary surface-relief was generated into one side of a quartz substrate through a plasma-etching process, and the parabolic profile was generated into a thick photoresist deposited on the other side of the quartz substrate. Calculations showed that a diverging parabolic lens with a f-number of 0.5 would deliver the desired optical pattern of multiple beams distributed over 90 degrees . A surface-relief depth of 6.0 mum was calculated with consideration of the phase distributions of such lens. The parabolic profiles were fabricated in a 10-mum-thick photoresist, by use of a contact exposure through a mask with a space pattern of repetitive 4- and 6-mum lines. He-Ne laser light was passed through a device that generated three parallel lines over a 90 degrees angle. The resulting diffraction patterns were characterized, and a satisfying result was obtained. The resulting multiple-line pattern can be used in robot vision and other applications.
authors: L G
authors: LG
authors: Neto
authors: L B
authors: LB
authors: Roberto
authors: P
authors: P
authors: Verdonck
authors: R D
authors: RD
authors: Mansano
authors: G A
authors: GA
authors: Cirino
authors: M A
authors: MA
authors: Stefani