2024年1月12日发(作者：)

了解

ZEMAX不计算光栅衍射效率，所以不能设置闪耀光栅。ZEMAX中光栅相关的有：类型（全息或者刻划）、刻线数、衍射级次、基底面型（平面、凹面或者环面等）。只有将光栅后面的光学元件摆对位置，ZEMAX才会将衍射光线画出来。所以需要用好坐标断点和solve中的chief ray。

Diffraction Grating______

The diffraction grating surface can be used to model straight-line ruled gratings.

The grating lines are parallelto the local x-axis. Other orientations can be simulated

by using a coordinate break surface before and after thegrating surface（在序列模式中由于没有非序列中的旋转选项，所以需要用到坐标断点面）. For a plane grating,

rays traced to the grating are refracted according to the equation

where d is the grating spacing (always in micrometersμm), is the refracted

angle, is the incident angle, Mis the diffraction order, is the wavelength (always in

micrometersμm), n1and n2are the indices of refraction beforeand after the

grating(透射式光栅的n1and n2该如何确定), and T is the grating frequency in lines

per micrometer. Note that the sign convention for Mis completely arbitrary. ZEMAX

uses the definition for T (lines per micrometer) rather than d (micrometers perline).

The grating surface can be plane, spherical, or conical, and the medium before the

grating, as well as thegrating itself, can be air, glass, "MIRROR" or any other valid

glass type. The grating is described by the y-spacingof the grating lines measured in

lines per micrometer (independent of the system units) and the diffraction order.

ZEMAX only models gratings to the extent of deviating ray paths. Other

properties, such as efficiency, and relativetransmission are not supported. If the

grating spacing is too small (or if T is too large) to satisfy the grating relation,then a

"Ray missed surface" error will be reported.

Standard Lens______

The standard lens is a lens composed of standard ZEMAXsurfaces. Standard

surfaces may be planes, spheres, conic

aspheres,or standard

lens is composed of5 separate sections:

1) A standard shape front face.

2) A standard shape rear face.

3) An annular ring between the clear

aperture of the front faceand the edge of the

front face.

4) An annular ring between the clear

aperture of the rear faceand the edge of the

rear face.

5) A possibly tapered cylindrical surface

connecting the edgesof the front and rear faces of the lens.

9 parameters are used to define a standard lens:

1) The radius of curvature of the front face. Use zero for infinity (flat).

2) The conic constant of the front face.

3) The semi-diameter to the clear aperture of the front face. Use a negative

value to yield the hyperhemisphericsag point.

4) The radial aperture to the edge of the front side of the lens.

5) The center-to-center thickness of the lens.

6) The radius of curvature of the rear face. Use zero for infinity (flat).

7) The conic constant of the rear face.

8) The semi-diameter to the clear aperture of the rear face. Use a negative value

to yield the hyperhemisphericsag point.

9) The radial aperture to the edge of the rear side of the lens.

All5surfaces may refract, reflect, or absorb light, depending upon the material

properties.

The reference point is the center of the front face of the lens. Coating/Scatter

Groups: Front face CSG #1,back face CSG #2, all other faces CSG #0.

Diffraction Grating_________

The diffraction grating is very similar to a Standard Lens, with 2additional

parameters:

1-9: See the Standard Lens description for information on theseparameters.

10: The grating line frequency in lines/micrometer on

the frontface.

11: The diffraction order for the front face.

The grating is assumed to consist ofequally spaced

linesparallel to the local x axis. The grating frequency is

the lines permicrometer along the y direction;

projected down on to the surface.

This object does not diffract rays correctly if the front diffractivesurfaceis made

hyperhemispheric.

For important information on diffractive objects, see “Diffraction from NSC

objects” on page 347.

Coating/Scatter Groups: Front face CSG #1, back face CSG #2, all other faces CSG

#0.

Rectangular Pipe Grating_______

This object is the same shape as the Rectangular Pipe and uses the same first 9

parameters. However, thegrating version adds a linear diffraction grating on all four

sides. There are two additional

parameters:

10: The grating line frequency in

lines/micrometer on the side faces.

11: The diffraction order. Multiple

orders may be specified, see “Diffraction

tab” on page 350.

The grating consists of equally

spaced lines perpendicular to the local z

axis, lying on each of the four

grating frequency is the lines per

micrometer along the z direction;

projected down on to either the XZ or

YZplane. Note the grating exists on all four sides of the pipe. The reference point is

the center of the front open face.

For important information on diffractive objects, see “Diffraction from NSC

objects” on page 347.

Coating/Scatter Groups: All faces CSG #0.

Rectangular Volume Grating_______

This object is the same shape as the Rectangular Volume and uses the same first

9 parameters. However, thegrating version adds a linear diffraction grating on four

faces of the object: the top, bottom, left,

and right faces.

There is no grating on the front or back

faces. There are two additional parameters:

10: The grating line frequency in

lines/micrometer on the side faces.

11: The diffraction order. Multiple

orders may be specified, see “Diffraction tab”

on page 350.

The grating consists of equally spaced

lines perpendicular to the local z axis, lying

on each of the four grating

frequency is the lines per micrometer along the z direction; projected down on to

either the XZ or YZplane. Note the grating exists on all four sides of the volume. The

reference point is the center of the front face.

For important information on diffractive objects, see “Diffraction from NSC

objects” on page 347.

Coating/Scatter Groups: Front face CSG #1, back face CSG #2, all other faces CSG

#0.

Diffraction from NSC objects———《ZEMAX347》

Some NSC objects have one or more diffractive faces; such as the Diffraction

Grating, Binary 1, and Binary 2objects. These objects refract or reflect rays as well as

diffract them, according to the grating period or phase andthe diffraction order and

wavelength. For any ray, if the diffraction order being traced does not satisfy the

gratingequation, then the energy of that ray will refract or reflect along the zero

order path.

Ray splitting is supported on diffractive surfaces, but splitting is only allowed by

order and not by reflected andtransmitted Fresnel coefficients. For this reason, no

"ghost" rays are generated from diffractive surfaces.

All diffractive NSC objects support a parameter to defined the "order" for

diffraction from the object. This orderis called the "primary" diffraction order.

Sequential rays which enter the non-sequential group through the entryport will

diffract only along the primary order.

Rays which originate from a non-sequential source will diffract only along the

primary order if ray splitting isoff. If ray splitting is on, then the diffraction may be

optionally controlled by the settings on the "Diffraction" tab ofthe Object Properties

dialog box. This tab includes optional settings which will split the ray by order;

allowing morethan one diffraction order to be simultaneously traced.

For more information on diffraction, see “Diffraction tab” on page 350.

The object properties dialog box---Diffraction tab《ZEMAX350》

For important information that applies to all diffractive objects, see “Diffraction

from NSC objects” on page 347.

The Diffraction tab is used to define the properties of diffractive surfaces. The

tab supports the followingcontrols:

Split: Selects how rays are split off from diffractive surfaces. The options are:

Don’t split by order: The rays will not split at the surface. Only the order defined

by the object parameterswill be traced, and all the transmitted energy goes into this

one order.

Split by table below: A user defined number of rays will be traced over a range of

integral orders. The fractionof energy given to each order is defined by the user in a

table.

Split by DLL function: An external DLL program is used to define which orders are

traced, how much energyeach order is given, and optionally, what the output ray

properties are (for user defined diffraction所有这些被选用的级次所对应的小数部

分的和为1，若不是则检测器上不会显示任何结果). For moreinformation on

defining Diffraction DLLs, see page 361.

DLL: The name of the DLL to use. This DLL must be placed in the DLLDIFFRACT

subdirectory of theOBJECTS directory. See “Directories” on page 59.

Start/Stop order: The beginning and ending order number. These numbers

determine how many cells in thetable are active; and how many times the DLL will be

called to compute the output ray properties.

Remaining controls: The remaining controls are used to define the parameters to

be passed to the DLL. Tomake these parameters variable or under

multi-configuration control, use the NPRO operand; for details see“NPRO” on page

473.

备注：

1.在看文献时，经常看到实验结果图中，其纵轴通常不是损耗单位，数据也是经过处理的，标以a.u.。请问这样做的意义何在以及处理办法。

答：arbitrary unit表示无单位，有可能是相对值，或者无量纲，一般都标注成a.u。一般所有纵坐标可以同时加上某个数或者减去某个数，这样可以把两个图合在一张，从而错开两个图，然后进行对比。

3和5就是通过加上一个数值使得图像位置上升，这样便于与1比较不如不这样处理，可能导致图像重合，不方便比较。

2.25%reflective, a 780.1nm VHG(volumetric holographic grating) was emplaced.用体全息光栅来减小和稳定巴条出射光束的频谱。

———《High-Resolution Spectral Mapping of a LensedHigh Power Laser Bar》

3.分贝