Two-Photon Absorption Calculator

Nonlinear Optics & Chemistry

Calculate two-photon absorption (TPA) transmission, output intensity, and absorption rate. Enter input intensity, TPA coefficient, sample length, and optional linear absorption. Supports multiple units.

Examples

See how to use the Two-Photon Absorption Calculator in real-world scenarios.

Two-Photon Microscopy

Two-Photon Microscopy

Calculate TPA transmission for a 0.2 cm sample, β = 1e-11 cm/W, I₀ = 1e4 W/cm².

Input Intensity (I₀): 10000 W/cm²

Intensity Unit: W/cm²

TPA Coefficient (β): 1e-11 cm/W

β Unit: cm/W

Sample Length (L): 0.2 cm

Length Unit: cm

High-Intensity Laser

High-Intensity Laser

A 1 mm sample, β = 2e-10 m/GW, I₀ = 5e8 W/m².

Input Intensity (I₀): 500000000 W/cm²

Intensity Unit: W/m²

TPA Coefficient (β): 2e-10 cm/W

β Unit: m/GW

Sample Length (L): 0.001 cm

Length Unit: m

Nonlinear Material

Nonlinear Material

A 0.5 cm sample, β = 5e-12 cm/W, I₀ = 2e3 W/cm², α = 0.02 1/cm.

Input Intensity (I₀): 2000 W/cm²

Intensity Unit: W/cm²

TPA Coefficient (β): 5e-12 cm/W

β Unit: cm/W

Sample Length (L): 0.5 cm

Length Unit: cm

Linear Absorption (α): 0.02 1/cm

α Unit: 1/cm

Spectroscopy Sample

Spectroscopy

A 2 mm sample, β = 1e-9 m/GW, I₀ = 1e9 W/m², α = 0.1 1/m.

Input Intensity (I₀): 1000000000 W/cm²

Intensity Unit: W/m²

TPA Coefficient (β): 1e-9 cm/W

β Unit: m/GW

Sample Length (L): 0.002 cm

Length Unit: m

Linear Absorption (α): 0.1 1/cm

α Unit: 1/m

Other Titles
Understanding Two-Photon Absorption Calculator: A Comprehensive Guide
Master nonlinear optics and TPA with this tool.

What is Two-Photon Absorption?

  • Definition of TPA
  • Nonlinear Optical Process
  • Importance in Science
Two-photon absorption (TPA) is a nonlinear optical process where a molecule simultaneously absorbs two photons to reach an excited state. TPA is widely used in microscopy, photonics, and material science.
TPA in Nonlinear Optics

TPA Examples

  • TPA enables deep-tissue imaging in two-photon microscopy.
  • Nonlinear materials are characterized by their TPA coefficients.

Step-by-Step Guide to Using the Calculator

  • Inputting Parameters
  • Selecting Units
  • Interpreting Results
To use the calculator, enter the input intensity, TPA coefficient, sample length, and optionally linear absorption. Select the appropriate units for each parameter. The calculator will compute the output intensity, TPA absorption rate, transmittance, and absorbed energy fraction.
How to Use the Tool

Usage Examples

  • Set I₀, β, and L to calculate TPA transmission.
  • Add α for samples with significant linear absorption.

Real-World Applications of TPA

  • Two-Photon Microscopy
  • Laser Material Processing
  • Spectroscopy and Sensing
TPA is essential in two-photon microscopy for deep-tissue imaging, in laser material processing for precise ablation, and in spectroscopy for studying nonlinear optical properties.
Applications in Science and Industry

Application Examples

  • Two-photon microscopy uses TPA for high-resolution imaging.
  • TPA is used to characterize new photonic materials.

Common Misconceptions and Correct Methods

  • Mixing Up Units
  • Ignoring Linear Absorption
  • Incorrect Formula Application
A common mistake is using inconsistent units or neglecting linear absorption. Always ensure all values are in compatible units and use the correct formula for TPA transmission.
Avoiding Calculation Errors

Misconception Examples

  • Don't use cm/W for β with m/GW for intensity.
  • Include α if the sample has significant linear absorption.

Mathematical Derivation and Examples

  • TPA Transmission Equation
  • Unit Conversions
  • Worked Example
The TPA transmission equation is: Iₗ = I₀ exp(-αL) / (1 + βI₀L exp(-αL)). Ensure all parameters are in compatible units before calculation.
Sample Calculation

Mathematical Examples

  • For I₀ = 1e4 W/cm², β = 1e-11 cm/W, L = 0.2 cm, Iₗ ≈ 8333 W/cm².
  • For I₀ = 5e8 W/m², β = 2e-10 m/GW, L = 0.001 m, Iₗ ≈ 454545454 W/m².