Optical medium

An optical medium is material through which electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. The medium has an intrinsic impedance, given by

${\displaystyle \eta ={E_{x} \over H_{y}}}$

where ${\displaystyle E_{x}}$ and ${\displaystyle H_{y}}$ are the electric field and magnetic field, respectively. In a region with no electrical conductivity, the expression simplifies to:

${\displaystyle \eta ={\sqrt {\mu \over \varepsilon }}\ .}$

For example, in free space the intrinsic impedance is called the characteristic impedance of vacuum, denoted Z₀, and

${\displaystyle Z_{0}={\sqrt {\mu _{0} \over \varepsilon _{0}}}\ .}$

Waves propagate through a medium with velocity ${\displaystyle c_{w}=\nu \lambda }$, where ${\displaystyle \nu }$ is the frequency and ${\displaystyle \lambda }$ is the wavelength of the electromagnetic waves. This equation also may be put in the form

${\displaystyle c_{w}={\omega \over k}\ ,}$

where ${\displaystyle \omega }$ is the angular frequency of the wave and ${\displaystyle k}$ is the wavenumber of the wave. In electrical engineering, the symbol ${\displaystyle \beta }$, called the phase constant, is often used instead of ${\displaystyle k}$.

이상화된 표준 기준 상태(온도에 대한 절대 0과 같은)인 자유 공간에서 전자파의 전파 속도는 c₀:^[1]

${\displaystyle c_{0}={1\over {\sqrt {\barepsilon _{0}\mu_{0}}},}$

여기서 $\epsilon {\displaystyle {}_{}}$ ${\$은 전기 상수이고 ${\displaystyle \mu {}_{}}$ ${\displaystyle 0_{}}$은 자기 상수$displaystyle ~\mu _{0}\}$

일반적인 소개는 Serway^[2] Sterway를 참조하십시오. 합성 미디어에 대한 자세한 내용은 Joannopoulus를 참조하십시오.^[3]

광학 매체의 종류

1. 균질 매체
2. 이질적인 매체
3. 투명매체
4. 반투명 매체
5. 불투명체

참고 및 참조

참고 항목

• 체렌코프 방사선
• 전자기 스펙트럼
• 전자기 복사
• 광학
• SI 단위
• 여유 공간
• 메타물질
• 포토닉 크리스털
• 광결정섬유