全息模式波前传感器中高阶衍射抑制方法研究

Suppression of High Order Diffraction in Holographic Wave-Front Sensor

全息模式波前传感器(HWFS)是一种模式型的波前传感器,它利用多模复合的全息元件和位敏探测器来获得入射光中特定模式Zernike像差的强度。然而,多模复合全息元件中的光衍射过程通常会伴随着高阶衍射产生的干扰光。这些干扰光会分散激光能量,降低探测信噪比。提出一种通过引入强度调制的方法来消除由二元相位型全息元件衍射产生的干扰光。该方法不仅可以应用于全息模式波前传感器中干扰光的消除,也适用于其他基于二元相位型全息元件的应用,如全息成像、像移干涉仪、光束偏转器等。

A holographic wave-front sensor(HWFS)is a modal wave-front sensor,which utilizes a multi-mode composite holographic element and a position sensitive photodetector to extract the amplitudes of specific Zernike modes from the incident light.However,disturbing light from high order diffraction of the multi-mode composite holographic element is inevitable.The disturbing light disperses the power of the incident light and decreases the signal-to-noise ratio of the sensor.Here,an intensity modulation method is introduced to eliminate the interference light generated by the diffraction of binary phase holographic elements.The proposed method can be used for the elimination of interference light in the holographic mode wavefront sensor,and it is suitable to other applications based on binary phase holographic elements,such as holographic imaging,phase-stepping interferometers,and beam deflectors.