Create an Account  |   Log In

View All »Matching Part Numbers


Your Shopping Cart is Empty
           

2DSI Few-Cycle Pulse Characterization: 4 - 50 fs


  • Two-Dimensional Spectral Shearing Interferometry
  • No Calibration Required
  • Direct Representation of Spectral Group Delay

2DSI

Related Items

2DSI Optics
Overhead View Showing Optical Layout
Click to Enlarge

2DSI Advantages

  • Avoids Sensitive Calibration
  • Direct Reconstruction, No Iterative Search Algorithm Required
  • 50 Attosecond Phase Delay Precision
  • Dispersion Free
  • Octave-Spanning Bandwidth
  • Fundamental and Up-Converted Spectrum Measured in Same Device
  • Fully Automated
  • Guide Laser for Easy Set Up

Thorlabs' solution for measuring sub-two-cycle pulses is Two-Dimensional Spectral Shearing Interferometry (2DSI). 2DSI measures an ultrashort pulse envelope by interfering neighboring spectral components. This technique was developed in close collaboration with MIT.

2DSI overcomes certain disadvantages in other femtosecond pulse measurement techniques by encoding the spectral group delay in the spectrum of a single nonlinearly transformed pulse, rather than two. This avoids the need to calibrate the delay between two pulses to high precision, a potential complication with other techniques for few-cycle pulses and below. In addition, the interferogram produced by 2DSI is a direct representation of the spectral group delay of the pulse, allowing for reconstruction of the pulse shape without the need for iterative search algorithms.

This allows 2DSI to accurately measure the spectral group delay of pulses with time-bandwidth products in excess of 20, precisely resolving all pulse features, such as weak satellite pulses, which other techniques can miss. The 2DSI geometry also inherently avoids having the pulse pass through any dispersive materials and uses type II up-conversion with a phase-matching bandwidth of nearly an octave.

Thorlabs' 2DSI automates the measurement process so that the only user intervention required is the initial alignment, which is made simple by a green counter-propagating alignment laser. The mechanical setup is based on our proven flexure stage design for all critical components. Long-term hands-off operation was one of the major design goals. A high-quality, high-dynamic-range spectrometer allows for simultaneous measurement of both the 2DSI inteferogram and fundamental spectrum.

Item #2DSI
Wavelength650 - 1000 nm
Pulse Width*4 - 50 fs
Time-Bandwidth Product>20 (Max)
Spectral Phase Precision50 attoseconds
Pulse Energy1 nJ - 1 µJ
Single ShotNo
Refresh RateUp to 10 Hz
Dimensions326 mm x 240 mm (12.85" x 9.45")

*Longer pulse widths are available upon request.

The left graph in the software screenshot below shows raw 2DSI traces. The raw data allows for an intuitive and qualitative estimate of the chirp on the pulse under test. Any deviation from a horizontal line is an indication of a non-transform limited pulse. In this screenshot, the top right graph shows Group Delay vs. Wavelength, while the lower right graph is a reconstructed temporal pulse shape.

2DSI Screenshot

Pulse Measurement with 2DSI

To demonstrate the measurement capabilities of the 2DSI, we used our Octavius 2P femtosecond laser, which was optimized for a pulse width limit of 9 fs. First, the pulse is dispersed by transmission through air. Then, the pulses undergo five reflections from dispersion compensating mirrors to compensate for the dispersion. To further compensate the dispersion, the pulses pass through a thickness of fused silica glass. The pulse width is then measured by the 2DSI.

Figure 1 shows the measured pulse width vs. the thickness of fused silica. Notice that between 2 and 3 mm of fused silica, the pulse width is very close to its theoretical minimum. With a fused silica thickness greater than 3 mm, the pulse width begins to increase, due to negative dispersion.

Figure 2 shows a screen shot of the 2DSI GUI interface taken during the measurement. The lower right panel shows the measured pulse in yellow, which is similar to the theoretical pulse in blue.

Click the Support Documentation icon document icon or Part Number below to view the available support documentation
Part Number Product Description
2DSI Support Documentation 2DSI : Two-Dimensional Spectral Shearing Interferometer, 650 – 1000 nm

Please Give Us Your Feedback
 
Email   Feedback On
(Optional)
Contact Me:
Your email address will NOT be displayed.
 
 
Please type the following key into the field to submit this form:
Click Here if you can not read the security code.
This code is to prevent automated spamming of our site
Thank you for your understanding.
  
 
Would this product be useful to you?       Little Use    1 2 3 4 Very Useful

Enter Comments Below:
 
Characters remaining 8000    
Posted Comments:
No Comments Posted
Click on any phrase below to search our site using our new Search Engine:
chirp   cycle   femtosecond   Frequency Resolved   FROG   idesta   idestaqe   interferometer   interferometry   meaurement   pulse   pulse characterization   pulses   shearing   sub   two   two-dimensional   ultrafast   ultrashort  
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal/Imperial Price Available / Ships
2DSI Support Documentation
2DSI Two-Dimensional Spectral Shearing Interferometer, 650 – 1000 nm
$25,000.00
Lead Time
Log In   |   My Account  |   Contact Us  |   Privacy Policy  |   Home  |   Site Index
Regional Websites: East Coast US US | Europe | Asia | China | Japan
Copyright 1999-2014 Thorlabs, Inc.
Sales: 1-973-579-7227
Technical Support: 1-973-300-3000


High Quality Thorlabs Logo 1000px: Save this Image