THORLABS FSAC User Manual Download Page 22

Interferometric Autocorrelator

 

Chapter 8: Specifications

 

Page 20

 

TT121442-D02 

Chapter 8  Specifications 

8.1.  General Specifications 

 

General Specifications 

Full Scan Range

 

50 fs to 10 ps 

Input Pulse Duration

 

Without Precompensation

40 fs - 1 ps (FWHM)  

With Precompensation

5

 

15 fs - 1 ps (FWHM) 

Full Scan Rate 

5 Hz 

Noise-Equivalent Sensitivity 

10

W

 at 800 nm for Ø1 mm Beam (

1/e

6

 

Input Wavelength Range 

650 nm to 1100 nm 

Input Polarization

 

Horizontal 

Input Beam Diameter 

<Ø4 mm (

1/e

 

Input Repetition Rate 

>300 kHz

7

 

Required Sampling Rate

 

>1.5 MHz for 10 ps Delay at 650 nm 

>150 kHz for 1 ps Delay at 650 nm 

Internal Dispersion 

GDD 

230 

fs

 at 800 nm (Nominal) 

TOD 

345 

fs

 at 800 nm (Nominal) 

Maximum Average Power 

150 mW 

Dimensions 

6.90" x 5.53" x 4.82" 

(175.3 mm x 140.4 mm x 122.4 mm) 

 

8.2.  Electrical Requirements 

Electrical Requirements 

Input Voltage 

±12 VDC 

Power Consumption 

6 W (Max) 

Connector 

Lumberg RSV3-657/2M Female Connector 

 

FSAC is designed to use the included Thorlabs LDS1212 power supply, which meets these requirements. 

8.3.  Environmental Requirements 

 

Environmental Requirements 

Room Temperature Range 

17 °C to 25 °C 

 

 

 

                                                      

5

 Pulses as low as 15 fs may be measured with use of dispersion compensation. 

6

 Sensitivity is defined as the noise-equivalent product of the average power and the peak power of the laser. 

7

 Lower repetition rates are possible when using triggered acquisition. 

Summary of Contents for FSAC

Page 1: ...FSAC Interferometric Autocorrelator User Guide...

Page 2: ...roblems 9 4 4 1 Sampling Rate 9 4 4 2 Photodiode and Amplifier Bandwidth 10 4 4 3 Saturation 11 4 4 4 Excessive Chirp 11 4 4 5 Peak to Background Ratio Too High Low 12 4 5 Measuring Short 40 fs Pulses...

Page 3: ...ol Description Direct Current Alternating Current Both Direct and Alternating Current Earth Ground Terminal Protective Conductor Terminal Frame or Chassis Terminal Equipotentiality On Supply Off Suppl...

Page 4: ...aser energy onto the retina Follow all safety precautions in the operator s manual 1 Never aim any laser at a person s eye skin or clothes 2 Always use proper laser safety eyewear 3 Avoid wearing watc...

Page 5: ...the delay between them and recombines the pulses at a photodiode Because the photodiode is not responsive over the fundamental wavelength band of typical Ti sapphire lasers two photon absorption is r...

Page 6: ...ld fall between 1 and 10 W If the peak average power exceeds this level then the average laser power of the beam entering the FSAC should be attenuated by using a neutral density filter or a Fresnel r...

Page 7: ...90 degrees Attach the VRC2SM1 fluorescent alignment target to the alignment aperture of the FSAC Figure 3 The input aperture iris and the fluorescent alignment target provide two points which define t...

Page 8: ...o the table M1 is adjusted to set the height of the beam and M2 is used to level the beam usually in alternating fashion The FSAC may be moved towards M2 to check the height and away from M2 to check...

Page 9: ...M2 to center the beam on the fluorescent alignment disk Note that when the FSAC is grossly misaligned spurious reflections may appear on the alignment target so be sure to look for the brightest spot...

Page 10: ...s maximum value and monitor the delay output to verify that the stage is moving The delay output should be roughly sinusoidal though it may be somewhat distorted due to nonlinear coupling between the...

Page 11: ...off on the oscilloscope to 100 ms to avoid triggering off of both the forward and backward scan Next adjust the photodiode amplifier gain to maximize the signal to noise ratio without saturating the p...

Page 12: ...tely resolve the envelope to estimate the pulse width 4 4 2 Photodiode and Amplifier Bandwidth The nominal detector bandwidth for each gain setting is shown in Table 1 For low gain settings the bandwi...

Page 13: ...tenuated by using a neutral density filter or a Fresnel reflection from an uncoated window for example For an 800 nm 1 mm 1 beam saturation occurs when the product of the average and peak power of the...

Page 14: ...t the reference mirror alignment in order maximize the peak to background ratio To do this begin by removing the FSAC lid using a 5 32 balldriver or the included 5 32 stubby hex key Next with the devi...

Page 15: ...ulse bandwidth and consequently the transform limited pulse duration are already known then a system of equations can be derived and solved to estimate the pulse width entering the FSAC Referring to F...

Page 16: ...the full width of the pulse so that the pulses no longer overlap in the combined beam there is no interference and the photodiode signal is at a minimum Figure 11 FSAC Optical Layout As photocurrent...

Page 17: ...e is assumed to be either a Gaussian or secant squared shape in which case the full width half maximum FWHM of the upper envelope2 of the autocorrelation trace will be directly proportional to the FWH...

Page 18: ...y autocorrelation with background 9 Using points near the beginning and end of the trace estimate the background and subtract it from the intensity autocorrelation trace to get the background free int...

Page 19: ...er 5 Theory and Interpretation Rev B May 1 2017 Page 17 Figure 13 An interferometric autocorrelation of a chirped pulse transitions to an intensity autocorrelation in the wings Pulse width estimation...

Page 20: ...metric Autocorrelator Chapter 6 Maintenance Page 18 TT121442 D02 Chapter 6 Maintenance The FSAC does not require regular maintenance To maximize lifetime of the device be sure it is powered off when n...

Page 21: ...r needs to purchase additional installation or inspection services if the system is moved from the original installation point The buyer must provide the appropriate utilities and operating environmen...

Page 22: ...y at 650 nm Internal Dispersion GDD 230 fs at 800 nm Nominal TOD 345 fs at 800 nm Nominal Maximum Average Power 150 mW Dimensions 6 90 x 5 53 x 4 82 175 3 mm x 140 4 mm x 122 4 mm 8 2 Electrical Requi...

Page 23: ...1 0 Tapped Hole 6 35 mm Deep for 25 0 mm Pillar Post 3 Places Permanently Attached Adjustable Iris SM1D12D with Internal SM1 1 035 40 Threads 0 14 Deep Removable End Cap SM1CP2 Port Used for Alignment...

Page 24: ...Interferometric Autocorrelator Chapter 9 Declaration of Conformity Page 22 TT121442 D02 Chapter 9 Declaration of Conformity...

Page 25: ...her Thorlabs products such as Pure OEM products that means assemblies to be built into a unit by the user e g OEM laser driver cards Components Mechanics and optics Left over parts of units disassembl...

Page 26: ...nada and South America Thorlabs Inc sales thorlabs com techsupport thorlabs com Europe Thorlabs GmbH europe thorlabs com France Thorlabs SAS sales fr thorlabs com Japan Thorlabs Japan Inc sales thorla...

Page 27: ...www thorlabs com...

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