Study On The Uniform Achromatic Light Beam Shaping Thin Film Devices

The light scattering thin-film is one of the important optical devices for light-shaping.In general,the scattering mode of thin-film device is divided into surface scattering type and bulk scattering type,which the micro-structures of the substrate surface or scattering particles in the matrix material are used to diffuse incident light.Light scattering films can be used in illumination,LCD backlight display,projection systems and other applications.Which have the disadvantages of low transmittance,scattering angle and wave shape uncontrollable in the domestic production of thin films.We use that a working wavelength of 405nm solid-state laser,the random micro-structures with uniform probability density function distribution is formed on the photoresist plate by means of point by point exposure.The achromatic uniform light film was designed,which has many advantages such as uniform intensity distribution of output light,achromatic,controllable scattering angles and wave shape.The main content of this paper includes the following parts:Firstly,the present research background of the subject and several types of light-shaping optical thin-films were briefly addressed,and put forword advantages and disadvantages of each light-shaping device.Second,the light scattering from random rough surface is analyzed by theoretical derivation.It is proved that the V-type micro-structures with uniform probability distribution has an achromatic and uniform light characteristics.Next,the influences of output wave amplitude and scattering angles caused by the change of micro-structure parameters were analyzed.Third,the achromatic and uniform with rectangular and circular specks of thin film samples were fabricated by experiments.The AZP4620 photoresist was coated to a thickness of around 12?m on the glass substrate and the exposure response characteristics was tested.A laser with wavelength of 405nm was used as the light source,the random micro-structures were formed on the photoresist plate after the development by pointwise exposure.The micro-structure parameters of the flims surface were measured by laser confocal microscopy,and the concrete structural parameters were obtained.The results show that the theoretical calculation value of the scattering angle is consistent with the actual measured value,and the correctness of the theoretical derivation is verified.In this paper,we photofabrication of light-shaping optical thin-films,it's much better than that most of the light scattering thin-films and lighting component on the market.It has great application value in illumination and LCD backlight display.