英语翻译The particular form of the wavefront emerging from a rea

英语翻译
The particular form of the wavefront emerging from a real lens can be exceedingly complex,since it is generally the result of a number of random errors in the design,fabrication,and assembly of the lens.Nevertheless,lenses that are well made and carefully assembled do possess certain aberrations that are inherent in their design.These aberrations give rise to well defined test patterns,and it is conventional to refer to such test patterns as evidence of the existence of a certain aberration,regardless of whether the particular pattern was caused by an inherent defect of the lens or a circumstantial combination of manufacturing errors.The test patterns caused by the basic aberrations of lenses are thus of considerable importance.In this section,the general characteristics of the primary monochromatic aberrations of rotationally symmetrical optical systems are reviewed.To describe the aberrations of such a system,we specify the shape of the wavefront emerging from the exit pupil.For each object point,there will be a quasi-spherical wavefront converging toward the paraxial image point.A particular image point is specified by giving the paraxial image coordinates (x0,y,),as shown in Fig.12.The wavefront can be expanded as a power series in the four variables (x,y) (the exit pupil coordinates) and (x0,y0) (the coordinates of the image
point).Due to rotational symmetry,the wavefront distribution W must not change if there is a rigid rotation of the x0,y0 and x,y axes about the z axis.It is possible to select the coordinate system such that the image point lies in the plane containing the x and z axes so y,is identically equal to zero.Hence,W can be expanded as
(See Welford (1974),p.87,or Welford (1986),p.107 for more details of the justification of writing W in the form given in Eq.(31).)
As described in Section III,the first term of Eq.(31) represents what is commonly called defocus,a longitudinal shift of the center of the reference sphere,while the second term represents a transverse shift of the center of the reference sphere,commonly called tilt.The third term gives rise to a phase shift that is constant across the exit pupil.It does not affect the shape of the wavefront,and consequently has no effect on the image.When considering monochromatic light,these three terms normally have coefficients equal to zero.However,these terms have nonzero coefficients for broadband illumination,and give rise to the chromatic aberrations of Section X.
The six terms with coefficients to are of fourth degree in variables x,y,and x0 when expressed as wavefront aberrations,and are of third degreewhen expressed as transverse ray aberrations.Because of this,these terms areeither known as fourth-order or third-order aberrations.Since they are most commonly known as third-order aberrations,we will be referring to them as third-order aberrations.

这一特定形式的一个真正的波前刚刚从镜头可能非常复杂的,因为它通常是由于数项随机误差的设计、制造和装配的镜头.不过,镜片精心打造的,而且精心组装做具有某些畸变是内在于在他们的设计中.这些畸变引起的定义时,测试的效果测试模式,是传统的指该等测试的模式,存在的证据一定畸变、无论是否自己的特定模式的一种固有的缺陷是由于透镜或间接结合制造误差.测试模式的基本畸变引起的镜头被因此颇为重要的.在这一节中,文学的一般特征主要单色畸变旋转对称光学系统的研究进展进行了综述.描述了畸变的这样一个系统,我们指定形状的波前正从出口的学生.为每个对象的观点,将会有quasi-spherical波阵面朝傍轴图像收敛点.指定一个特定的图像点是通过给傍轴图像坐标(x0、y、),显示在图12.波阵面,可以扩展为幂级数在四个变量(x,y)(出口瞳孔坐标)和(x0、y0)(的坐标的形象
点).由于旋转对称性,波阵面分布W必须不会改变的,即使有一个刚性旋转,y0 x0、x、y轴关于z轴.这是可能的,这样的选择坐标系统的图像点在于飞机包含x轴和z轴那么y,是同等于零.因此,W可以扩展
(见Welford(1974年),p.87,或Welford(1986年),p.107为更多的细节的证写作的形式给出了W的情绪智商.(31).)
第三章所述,第一学期的情商.(31)代表通常被称为defocus,纵向转移referen的中心