| 查看: 1313 | 回复: 5 | ||
jc_168木虫 (正式写手)
|
[求助]
关于强激光激发的电磁场问题
|
|
The laser beams can produce electromagnetic fields whose intensity can reach very high values, beyond what is possible with other sources of electromagnetic radiation. In principle, it becomes possible to probe the fundamental properties of matter and verify the theories of physics under extreme conditions. In this exercise, you are asked to calculate the parameters of a laser beam as the maximum value of the energy density of the electromagnetic field corresponds to that associated with the energy density of matter at rest under relativistic (i.e. the formula mc^2). For your calculation, use the water density is 1 g/cm^3. Suppose that the laser beam is Gaussian transverse profile, the electric field of this beam is given by the following expression in the plane where it is a) Find the expression of the magnetic field associated with this beam. Neglect the longitudinal field components, i.e. along the axis z. b) Find the expression of the energy density of the electromagnetic field produced by this beam. Find the parameters of electric and magnetic fields that produce an energy density equal to that of matter at rest. Rate these extreme values of electric and magnetic fields, as well as the magnetic induction. c) Express the electromagnetic field in phasor notation. Find the expression of the average power per unit area (i.e. the intensity). What is the maximum intensity? d) What is the average power of this beam? Suppose a wavelength λ = 1 μm and a beam size w = 10 μm. e) In practice, we can not attain power with a continuous laser. It is necessary to use a pulsed laser. What is the energy of the laser pulse if its duration is 1 picosecond (1 ps = 10^-12 s)? f) What is the volume of medium required to produce the laser pulse is extracted if averaged 10^18 photons/cm^3 in this environment? [ Last edited by 华丽的飘过 on 2012-9-22 at 21:53 ] |
回复此楼» 猜你喜欢
国自科面上基金字体
已经有6人回复
-
304求调剂
已经有3人回复
-
304求调剂
已经有6人回复
-
材料与化工一志愿南昌大学327求调剂推荐
已经有8人回复
-
0703 物理化学调剂
已经有5人回复
-
化学工程321分求调剂
已经有7人回复
-
0703化学调剂 290分有科研经历，论文在投
已经有7人回复
-
308求调剂
已经有3人回复
-
本人考085602 化学工程 专硕
已经有10人回复
-
焦虑
已经有9人回复
» 本主题相关价值贴推荐，对您同样有帮助:
- 场发射性质可以用在哪些方面呢？
已经有4人回复
- 【2010征文】从实验看现代引力理论
已经有45人回复
jc_168
木虫 (正式写手)
- 应助: 15 (小学生)
- 金币: 14045.3
- 散金: 2
- 红花: 4
- 帖子: 320
- 在线: 204.7小时
- 虫号: 793178
- 注册: 2009-06-12
- 性别: GG
- 专业: 光子与光电子器件
2楼2011-10-04 00:30:23
3楼2011-10-04 16:02:05
4楼2011-10-08 10:06:39
5楼2011-10-10 00:33:45
6楼2011-11-16 22:16:30
