Speckle Pattern Of Light Research Articles

Toward multimode-fiber shape sensing.

We demonstrate machine-learning assisted dynamic tracking of the shape of a multimode fiber whose spatial configuration is manipulated by the movement of three linear stages. The data source used for the analysis is the coherent speckle pattern of light that has made a round trip in the fiber.

Ghost imaging with white light speckle patterns

In this paper we describe a method to study the formation of a ghost image by using a simplified setup. A spatial light modulator (SLM) working in amplitude regime is used both to display the object and the intensity distribution that provides the high-spatially correlated beams which are the base of this phenomenon. We compare the recovered ghost image with that obtained by using pseudothermal light. Moreover we show that good quality images are also retrieved when a turbulent media is present.

Security–orientated Plastic Optical Fiber sensor in Modalmetric Configuration

Abstract The article describes the operation's rule of the fiber optic sensor in the modalmetric configuration. This type of sensor is described by comparatively simple construction, while retaining other features of fiber-optic sensors such as high sensitivity. A modalmetric fiber optic sensor [1] , whose scheme is shown in Fig. 1, comprises a multimode sensor fiber, a light source for launching light into the multimode fiber to produce a multimode speckle pattern of light at an end of the fiber, a single mode fiber to receive light from the multimode speckle pattern and a detector connected to the single mode fiber to detect the received a partial light from the multimode speckle pattern. Any disturbance to the fiber which can cause a change in any one of the phase, polarization and distribution of the modes, will cause the speckle pattern to change. By measuring this change, a physical perturbation to the fiber such as a vibration or strain can be detected. This gives a very high potential application. In the paper presents, for example, possible application of the modalmetric sensor to protection of works of art and museum collections. The advantage of its use is the ability to tie the fiber in structure of material. Moreover, the advantage of such type a sensor compared to existing solutions of security sensors is the reaction for vibration and touch. The paper presents the concept and results of the system optimization.

다중모드 광섬유를 이용한 홀로그램 다중화 연구

We presented the holographic memory system using a multi-mode optical fiber. In this system, we multiplexed multiple holograms using the lights from multi-mode optical fibers as reference beams. The proposed system has two degrees of multiplexing freedom: speckle pattern of light coming from multi-mode fiber and spatial location of multi-mode fibers. Therefore, the data addressing in the system can be performed by mode and spatial multiplexings.

Formation of interference patterns during double-exposure recording of lens Fourier speckles

Within the Fresnel approximation we consider the formation of a speckle interferogram, sensitive to the inclination of the wave front or the derivative of the normal displacement of the object during its coherent illumination by either a diverging or converging spherical wave. This results in recording a Fourier transform speckle pattern of light diffusely scattered by the surface into the plane of the photographic place. It is shown, both theoretically and experimentally, that the sensitivity varies according to the variation of the Fourier transform scale.

Pseudocoloring method for 3-D contouring

The interference properties of white light speckle patterns obtained with an optical system not corrected for chromatic aberration are applied to pseudocolor encode the depth level contours of a 3-D diffusing object. As the first step, a recording of the different encoded images of depth levels is made. Secondly, a reconstructed pseudocolored image is obtained, where different color assignments can be tuned by changing the position of a spatial filter slit. Also, a quantitative contouring can be made by scanning the pseudocolored image plane with a spectroscopic device.

Contrast of white light speckle patterns at a defocused image plane

Contrast of white light speckle patterns at a defocused image plane