Speckle reduction in laser imaging applications using rotating magneto-optical disk

Abstract

Effective methods for speckle reduction are essential in improving the image quality of laser imaging applications. Accordingly, the present study proposes a novel technique for reducing the speckle contrast in laser imaging applications by means of the magneto-optic Kerr effect induced by a rotating magneto-optical (MO) disk. The performance of the proposed method is evaluated experimentally using a laboratory-built prototype model. The experimental results show that the rotating MO disk can reduce the speckle contrast of the captured image by 60% of the previous value. As a result, the proposed method yields an effective improvement in image quality. Overall, the proposed method provides a promising solution for improving the performance of a wide range of laser imaging applications.

Speckle reduction using phase plate array and lens array

“…Speckle is a drawback of laser display for it can downgrade the image quality greatly. To solve this problem, numerous methods have been proposed, such as: using a deformable mirror 3 or a scanning mirror 4,5 to realize angle diversity; using a broad-area vertical-cavity surface-emitting laser 6 or random lasers 7 to realize wavelength diversity; using a staircase element 8 or a refractive steppers 9 to realize optical path difference; rotating independent speckle patterns 10 or a magneto-optical disk 11 to realize polarization diversity; using a light pipe 12 or a multimode optical fiber bundle 13 to realize time averaging and so on. J. I. Trisnadi firstly proposed the speckle reduction method using Hadamard phase diffuser 14,15 .…”