Optical tools
Quick calculations for spectroscopy and ultrafast optics.
Light wavelength conversion
Convert wavelength, wavenumber, frequency, and photon energy.
- Wavelength (nm)
- 800
- Wavelength (µm)
- 0.8
- Wavenumber (cm⁻¹)
- 12,500
- Frequency (THz)
- 374.7406
- Photon energy (eV)
- 1.549802
Transform limit
Convert between spectral FWHM and transform-limited pulse duration.
Uses ΔνΔt = 0.441 and the narrow-band wavelength approximation.
Absolute Raman cross section
Evaluate the single A-term model from Trulson and Mathies using the fitted parameters in Table II.
9.1035e-29 cm² molecule⁻¹σR(ν₀) = K FA²(ν₀)
FA = ν²(νₑ² + ν₀²) / (νₑ² - ν₀²)²
Calculated vs. Table I
Mean absolute difference 5.0%
| λ₀ (nm) | Calculated (microbarn) | Table I (microbarn) | Difference |
|---|---|---|---|
| 647 | 91 | 90 ± 10 | +1.2% |
| 568 | 170 | 170 ± 20 | -0.3% |
| 514 | 276 | 300 ± 20 | -7.9% |
| 476 | 405 | 420 ± 30 | -3.5% |
| 407 | 913 | 800 ± 160 | +14.2% |
| 351 | 2,073 | 2,010 ± 300 | +3.1% |
Like Table I, the result is integrated over 4π, the scattered bandwidth, and outgoing polarizations. Uses the Table I wavelengths as printed. ν is the Stokes-scattered wavenumber ν₀ - νRaman, with frequencies converted to kK. K is converted from millibarn to microbarn; 1 microbarn = 10⁻³⁰ cm². The 608 cm⁻¹ value represents the summed 608/628 cm⁻¹ cacodylate feature, and 2900 cm⁻¹ represents the integrated cyclohexane CH envelope. This single-state expression is intended for preresonance interpolation, not the resonant limit. Paper ↗