Brillouin Stokes Cascade

Generate cascaded Brillouin Stokes frequencies from a pump and fixed shift.

Description

A Brillouin Stokes cascade subtracts a fixed frequency shift for each successive order.

A Brillouin Stokes cascade subtracts a fixed frequency shift for each successive order. GHz shifts are converted to THz before subtraction.^[1]

Generate cascaded Brillouin Stokes frequencies from a pump and fixed shift.

When to use Brillouin Stokes Cascade

Use this tool to generate cascaded Brillouin Stokes frequencies from a pump and fixed shift.

Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.

How to use Brillouin Stokes Cascade and understand its results

Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
Enter pumpFrequencyTerahertz, brillouinShiftGigahertz, stokesOrderCount using the field table and calculation rules, then run the tool.
Read stokesFrequenciesTerahertz, finalFrequencyTerahertz. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
pumpFrequencyTerahertz	Pump frequency (THz)	number; minimum: 0	Required
brillouinShiftGigahertz	Brillouin shift (GHz)	number; minimum: 0	Required
stokesOrderCount	Stokes order count	integer; minimum: 1; maximum: 100	Required

Enter nonnegative pump/shift and integer count 1–100. Reject any resulting frequency≤0. Return ordered cascade frequencies and final frequency.

frequency_k=pumpTHz−k shiftGHz/1000, k=1…count

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
stokesFrequenciesTerahertz	Stokes frequencies (THz)	list of number
finalFrequencyTerahertz	Final Stokes frequency (THz)	number; minimum: 0

json

{
  "input": {
    "pumpFrequencyTerahertz": 200,
    "brillouinShiftGigahertz": 10,
    "stokesOrderCount": 3
  },
  "output": {
    "stokesFrequenciesTerahertz": [
      199.99,
      199.98,
      199.97
    ],
    "finalFrequencyTerahertz": 199.97
  }
}

Limitations and assumptions

No wavelength-dependent shift, gain, threshold or generated power is predicted.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use B-Integral: Calculate nonlinear phase accumulation and compare it with a caller-defined B-integral limit. For a complementary task, use FWM Idler Frequency: Calculate degenerate four-wave-mixing idler frequency and wavelength.

References

Brillouin Stokes Cascade — tool.io

Similar or alternative tools

B-Integral
Calculate nonlinear phase accumulation and compare it with a caller-defined B-integral limit.
FWM Idler Frequency
Calculate degenerate four-wave-mixing idler frequency and wavelength.