Pump–Probe Delay Stage

Convert pump–probe delay to retroreflector displacement and quantized stage steps.

Description

A retroreflector delay stage changes optical path by twice its displacement.

A retroreflector delay stage changes optical path by twice its displacement. Quantizing displacement to stage steps introduces a signed delay error.^[1]

Convert pump–probe delay to retroreflector displacement and quantized stage steps.

When to use Pump–Probe Delay Stage

Use this tool to convert pump–probe delay to retroreflector displacement and quantized stage steps.

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 Pump–Probe Delay Stage 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 requestedDelayFemtoseconds, stageStepNanometers using the field table and calculation rules, then run the tool.
Read requiredDisplacementMicrometers, nearestStepCount, achievedDelayFemtoseconds, delayErrorFemtoseconds. 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
requestedDelayFemtoseconds	Requested optical delay (fs)	number	Required
stageStepNanometers	Stage step size (nm)	number; minimum: 0	Required

Enter finite signed requested fs delay and positive nm step. Return ideal displacement in µm, integer steps, achieved fs and achieved-minus-requested error.

displacement=c delay/2; steps=round(displacement/step); achievedDelay=2steps×step/c

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

Output field	Meaning	Value type
requiredDisplacementMicrometers	Retroreflector displacement (µm)	number
nearestStepCount	Nearest stage-step count	integer
achievedDelayFemtoseconds	Achieved optical delay (fs)	number
delayErrorFemtoseconds	Delay quantization error (fs)	number

json

{
  "input": {
    "requestedDelayFemtoseconds": 2000,
    "stageStepNanometers": 100
  },
  "output": {
    "requiredDisplacementMicrometers": 299.792458,
    "nearestStepCount": 2998,
    "achievedDelayFemtoseconds": 2000.0503148081198,
    "delayErrorFemtoseconds": 0.050314808119765075
  }
}

Limitations and assumptions

Rounding uses JavaScript Math.round, including negative half-step behavior. No travel limits, backlash or calibration is checked.

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 Swept-Frequency Distance: Convert swept-frequency phase slope to delay and one-way distance. For a complementary task, use Transient-Absorption Lifetime Fit: Fit a positive transient-absorption trace to a single exponential using log-linear regression.

References

Pump–Probe Delay Stage — tool.io

Similar or alternative tools

Swept-Frequency Distance
Convert swept-frequency phase slope to delay and one-way distance.
Transient-Absorption Lifetime Fit
Fit a positive transient-absorption trace to a single exponential using log-linear regression.