JJF 1493-2014 Calibration specification for ultrashort optical pulses autocorrelators
1 Scope
This specification is applicable to the calibration of ultrashort optical pulse autocorrelator with autocorrelation width of 10fs to 100ps.
2 Terms
2.1 ultrashort optical pulse
pulse of light radiation with a duration of femtosecond (fs) to picosecond (ps). It is also known as ultrashort laser pulse, ultrashort pulse or ultrafast laser.
2.2 autocorrelation of ultrashort optical pulse
curve of correlation intensity relative to time delay obtained with nonlinear optical effect by dividing the ultrashort pulse laser into two beams, applying variable time delay to one beam , and making the two pulses scan each other
3 General
Ultrashort optical pulse autocorrelator is the most commonly used instrument to measure the time domain width of ultrashort optical pulse, which is referred to as autocorrelator for short. The autocorrelator is a Michelson interferometer, which makes one pulse scan the other by virtue of optical delay, and detects the correlation signal by using the second-order nonlinear effect. The autocorrelator may be divided into collinear type and non-collinear type, as shown in Figure 1 (a) and Figure 1 (b) respectively.
(a) Collinear type (b) Non-collinear type
Figure 1 Structure of autocorrelator
4 Metrological characteristics
Indication error of autocorrelation width: ≤ 20%.
Note: The above indicators are not used for acceptance judgment, but for reference only.
5 Calibration conditions
5.1 Environmental conditions
5.1.1 Environmental temperature: (23±5)°C;
5.1.2 Relative humidity: ≤70%;
5.1.3 It is clean to avoid damage to equipment caused by dust;
5.1.4 Vibration and interference: There is no sensible air fluctuation or vibration, electromagnetic interference and background radiation affecting the measured data in the calibration area.
5.2 Measurement standard and other equipment
5.2.1 Standard autocorrelator
5.2.1.1 Measurement range of autocorrelation width: 10 fs to 100 ps;
5.2.1.2 Relative expanded uncertainty of autocorrelation width measurement: better than 16% (k=2).
5.2.2 Ultrashort pulse laser
5.2.2.1 Spectral range: (600 to 1600) nm;
5.2.2.2 Average power: ≥ 30 mW;
5.2.2.3 Power stability: better than 2% within 10 minutes;
5.2.2.4 The pulse autocorrelation width: 10 fs to 100 ps.
5.2.3 Other equipment
5.2.3.1 Laser attenuator: When the laser power is too high, it is placed in the measuring optical path to avoid damage to the measuring instrument;
5.2.3.2 Dispersion adjuster: Change the pulse width to the autocorrelation width calibration point by adjusting the amount of dispersion.
Foreword i
Introduction ii
1 Scope
2 Terms
2.1 ultrashort optical pulse
2.2 autocorrelation of ultrashort optical pulse
3 General
4 Metrological characteristics
5 Calibration conditions
5.1 Environmental conditions
5.2 Measurement standard and other equipment
6 Calibration items and methods
6.1 Calibration items
6.2 Block diagram of calibration device
6.3 Calibration preparation
6.4 Calibration methods
7 Calibration result
8 Recalibration time interval
Annex A Recommended format for inside page of calibration certificate
Annex B Recommended format for original calibration records
Annex C Example for evaluation of uncertainty
Annex D Commonly used deconvolution factors
