求助，帮师妹答几个光学题目，谢谢了

wangnachina · 发表于 2007-9-13 13:37:21

2)  Imagine  you  need  to  measure  an  optical  properties of a
surface: angular  distribution of  scattered radiation  (for each
wavelength).

How you would do this, using which device. What difficulties  and
which accuracy do you expect.

3)  Imagine  you  faced  a  situation  when  customer's  PLED

(Plane Light Emitter )

was simulated, but  the results  (spatial distribution  of brightness
over screen)  differs substantially  from what  was measured  (by
customer). The PLED  consists of a  CCFL tube, an  LGP with micro
dimples  on  its  bottom,  wrapped  in  a white plastic reflector
sheet, and a couple of DBEFs (this plates with microprisms)  laid
on its emitting surface. Even with DBEFs removed there remains  a
viable difference.

Specifications  of  geometry  and  CCFL  were  given by customer,
optical properties of reflector sheet and DBEFs were measured.

What  would  you  do.  Where  you  suspect  the  error. Which its
magnitude do you  consider normal (e.g.  caused by inaccuracy  of
measurement, deviation of CCFL instances etc).

4) Imagine you need  to measure which (scattering)  particles are
dispersed in a solution (e.g. paint). Expected size of  particles
is say

case A 10-500 nm,
case B  5-50 um

and concentration (volumetric) can be varied between say 0.5%  to
say 10%. How would you proceed. Which difficulties do you  expect
and which accuracy hope to achieve.

How  you  can  measure  their  spatial  distribution  if  it is
inhomegeneous.

5) Imagine you faced a fluorescent sample (solution or  surface).
How would you measure it? Which characteristics are pertinent  to
fluorescence? How they are defined? How to simulate  fluorescence
using it?

6) Imagine  a customer  device (pls  give SSML  scene). They  say
there is emitter  that is <  1/100 (!!) wavelength  in size. What
can such emitter be. How you can simulate it.

7) Do you  have experience with  CCD measuring cameras  and photo
diode sensors. How you estimate their strong and weak points  and
accuracy.  What  is  their  dynamic  range. How to measure sample
whose reflectance has WIDER range of brightness.

8) Imagine you need to simulate scattering by particles dispersed
in a clear plastic. They have cylindrical shape and are of size,
say

  case A < 0.1 um
  case B 1 to 5 um
  case C some 20-30 um

How would you proceed. Which data you need and which difficulties

and errors do you expect.

9) What are  different cases when  diffraction occurs in  optics?
What are their differences? How to simulate them.

Which method of solution of diffraction problems in optics (under
monochrome illumination) do you know. Which of them you operated.
What are their weak and strong points.

10)  Imagine  we  have  solution  of  a diffraction problem for a
snowflake under monochrome illumination, that is so-called  phase
function.

How  it  can  be  (resp.  can  not  be)  used  for  simulation of
scattering of sun light in a snow storm, e.g. to see bloom around
sun disk. What inaccuracies do you expect. How to do.

11) What is  light coherence. How  to measure it.  How it affects
scattering and  when. Pls  list coherence  characteristics of some
common light sources.

12) Imagine you have  a PLED (see pt  3). Dimples on LGP  surface
have spatially varied density, orientation, size and maybe shape.

These parameters,  or rather  their space  distribution, must  be
chosen  (designed)  so  as  to  achieve  e.g.  maximally  uniform
brightness of emitted light. Experience shows that e..g. size may
vary about order of magnitude from one edge to another, and  with
a proper  profile one  may achieve  nearly (+/-  a few percent or
less) brightness.

The work consists of two coupled phases: ANALYSIS (calculation of
characteristics of emission for GIVEN  distributions)  and
OPTIMISATION  STEP  (changing  those  distributions  by comparing
obtained and target emissions).

How you would do such a design. What simulation and  optimisation
method would you use. Which difficulties do you expect.

What are your estimates of required run time and memory.

13)  Design  of  paint  color.  Imagine  you  have  a  palette of
available pigments,  say 100  of them.  You need  to fabricate  a
paint with desired optical properties (notice that its color  may
depend on angle of observation/illumination).

Design consists  in choosing  which pigments  among available  to

use, and in which proportions (concentrations).

How would you  proceed. Which data  on pigments and  target paint
would you use. How the optimisation procedure can be organized.

As a result (this or that way) you got formulation of the  paint.
Now suppose it is  fabricated, applied, dried and  measured. What
deviation from predicted results do you expect. Why.

14)  Imagine  you  have  a  rough  surface (brushed metal). Which
measuring method do you suggest to measure its profile.

Imagine this was done, and the sample was simulated, The  results
however deviate from direct measurement of scattering. What  the
is the reason as you suspect.

15)  Imagine  that  in  a  measurement  you  need  to attenuate
illumination (change its amplitude better gradually but at  least
granularly),  Which attenuator will you use. What is  its  string
and weak points and expected accuracy.

shaka2007 · 发表于 2007-9-14 17:03:25

刚刚看到你的消息了，但是很抱歉，这些问题不是我的专长，没有办法回答你，如果是激光相关的还可以，应用光学这块我也在学习，看看其他人的回答吧

[ 本帖最后由 shaka2007 于 2007-9-14 17:04 编辑 ]

求助，帮师妹答几个光学题目，谢谢了

发表回复

浏览过的版块


热搜: 防雾膜棒料红外反射膜光电二极管镀膜机反射膜光谱仪光电探头真空镀银滤光片光器件应用光学 zemax激光远心镜头 sio2 增透膜离子源栅网 zemax 论文高反膜半反半透膜