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nnp:optics:optical_gain [2017/02/03 10:46]
stefan.birner [Optical Gain]
nnp:optics:optical_gain [2017/02/20 21:21] (current)
stefan.birner
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 ==== Physics model ==== ==== Physics model ====
-The transition rate per volume element can be expressed with the following sum:+The transition rate per volume element can be expressed with the following sum,
 \[ \[
-R = R_{ab} - R_{ba} = \frac{2}{V} \sum_{k_a} \sum_{k_b} \frac{2 \pi}{ \hbar} |H_{ba}| ^2 \delta(E_b - E_a -\hbar \omega)(f_a-f_b)+R = R_{ab} - R_{ba} = \frac{2}{V} \sum_{k_a} \sum_{k_b} \frac{2 \pi}{ \hbar} |H_{ba}| ^2 \delta(E_b - E_a -\hbar \omega)(f_a-f_b).
 \] \]
  
-In order to make evaluate the sum much faster we calculate the $H_{ba}$ matrix element at $k_a = 0; k_b = 0$ (Remark: $k_a = k_b$), and we neglect the k dependence of it.  +In order to evaluate the sum much faster we calculate the $H_{ba}$ matrix element at $k_a = 0; k_b = 0$ (Remark: $k_a = k_b$), and we neglect the $kdependence of it.  
-Then we can simplify the sum in the following formif the irradiation has the $\gamma(E, w)$ broadening function, where $E$ is the irradiation energy, and $w$ is the line width.  +Then we can simplify the sum as follows
 \[ \[
-R(E, w) = C_0(E) ​  ​\int ​dE_a dE_b \gamma(E_a-E,​ w) \cdot  H(E_a-E) \cdot  [n(E_a) - p(E_b)]+R(E, w) = C_0(E) ​  \int \gamma(E_a-E,​ w) \cdot  H(E_a-E) \cdot  [n(E_a) - p(E_b)] ​ {\rm d}E_a {\rm d}E_b,
 \] \]
 +where $E$ is the irradiation energy, $w$ is the line width and we assume that the irradiation has the $\gamma(E, w)$ broadening function.
  
-Here $C_0(E)$ is an energy dependent constant:+Here $C_0(E)$ is an energy dependent constant,
 \[ \[
-C_0 = \frac{\pi e^2 \hbar}{n_r c \epsilon_0 m_0^2 E}+C_0 = \frac{\pi e^2 \hbar}{n_{\rm r} c \epsilon_0 m_0^2 E}.
 \]  \] 
  
 ====Input file structure==== ====Input file structure====
  
-A new keyword has been introduced to handle an optical device, ​//opticaldevice{}//+A new keyword has been introduced to handle an optical device, ​''​opticaldevice{}''​.
  
 <​code>​ <​code>​
 opticaldevice{ opticaldevice{
  name = "​quantum_region_name"​  name = "​quantum_region_name"​
- line_broadening = 1            #Line broadening model (1: Lorentzian) + line_broadening = 1            # Line broadening model (1: Lorentzian) 
- photon_energy = 1              #Photon energy in (eV) + photon_energy ​  ​= 1.0          ​# Photon energy in (eV) 
- line_width = 1                 ​#Line width in (eV)+ line_width ​     = 1.0          ​# Line width in (eV)
 } }
 </​code>​ </​code>​
  
-An in the run paragraph you have to also add //solve_optical_device{}// in order to include it the simulation flow+The ''​run''​ keyword requires ''​solve_optical_device{}'' ​to be included.
  
 ==== Results ==== ==== Results ====
 <​figure>​ <​figure>​
 ;#; ;#;
-<​dataplot xlabel="​x(nm)" ylabel="​1/​s/​m^3"​ ylegends="​Gain">​+<​dataplot xlabel="​Position ​(nm)" ylabel="​Gain (1/s/m^3)" ylegends="​Gain" title="​Optical gain">
 -90 0 -90 0
 -85 0 -85 0
nnp/optics/optical_gain.1486118804.txt.gz · Last modified: 2017/02/03 10:46 by stefan.birner