Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010


Mounted BBO crystal for for Avoca-7 SPIDER

Part number CR-BBO-6-6-0.04 AR350-450 nm  request a quote
Dimensions 6X6X0.04 mm
Orientation theta = 43 degree and phi = 0 degree
Flatness less than lambda/8
BBAR coating 350-450 nm
 

Del Mar Photonics delivered Avoca SPIDER femtosecond measurement system and Rincon cross-correlator to University of Nebraska-Lincoln

 

Avoca SPIDER brochure - Avoca SPIDER manual - Avoca SPIDER software - request a quote

Rincon brochure - Rincon manual - Rincon software - request a quote

These items were ordered by Sudeep Banerjee.

 

Sample of Sudeep Banerjee research interests:

Abstract Submitted for the DAMOP05 Meeting of The American Physical Society

Optical detection and temporal characterization of an ultra-fast laser-produced electron beam
SUDEEP BANERJEE, SCOTT SEPKE, Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska, ANTHONY VALENZUELA, Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan, RAHUL SHAH, Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, DONALD UMSTADTER, Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska

The interaction of a laser-produced electron beam with an ultra-intense laser pulse in free space is studied. We show that the optical pulse with a0=0.5 imparts momentum to the electron beam, causing it to deflect along the laser propagation direction. The observed 3-degree angular deflection is found to be independent of polarization and in good agreement with a theoretical model for the interaction of free electrons with a tightly focused gaussian pulse, but only when longitudinal fieelds are taken into account. This technique is used to temporally characterize a sub-picosecond laser-wake field-driven electron bunch. Applications to modifying electron-beam properties (i.e., emittance, duration and energy spread) are also discussed.
 

All-laser-driven, MeV-energy X-ray source for detection of SNM
Banerjee, S.; Powers, N.; Ramanathan, V.; Cunningham, N.; Chandler-Smith, N.; Shouyuan Chen; Shadwick, B.; Umstadter, D.; Vane, R.; Schultz, D.; Beene, J.; Pozzi, S.
Technologies for Homeland Security, 2008 IEEE Conference on
Volume , Issue , 12-13 May 2008 Page(s):1 - 6

Summary:A quasi-monoenergetic MeV X-ray source based on laser-driven electron acceleration and Thomson scattering is under development at the Extreme Light Laboratory at the University of Nebraska, Lincoln. Reported are experimental results on the generation of high- brightness, nearly monoenergetic 300-MeV energy electron beams with the high power, short-pulse DIOCLES laser system. The laser system produces > 100 TW of maximum peak power per pulse. The maximum pulse energy is 3.5 J with a temporal duration of 30 fs. Energetic electron beams are produced by focusing a laser pulse with 40-50-TW peak-power on a supersonic helium nozzle to drive a relativistic plasma wave (laser wakefield). Electron beams with energies of 320 + 2.0 MeV are accelerated over a distance of 3 mm. The beam has an angular spread of 5 mrad with a charge of 100 pC. The use of a stable and well-characterized laser system - in conjunction with high temporal contrast and adaptive optics correction on the amplified beam (to obtain ideal focal spots) - has enabled generation of very reproducible electron beams, both in terms of energy and pointing stability. It is found that electron acceleration is most efficient, beam brightness is highest and reproducibility is best in the resonant regime, where the temporal duration of the laser pulse equals the plasma period. A beamsplitter is used after compression to generate two pulses in the ratio of 80% to 20%. The higher power pulse drives the laser wakefield to produce the energetic electron beams while the lower power pulse is transported through an independent line and focused on the electron beam to generate X-rays. Experiments are currently in progress to observe and characterize the X-ray beam. Theoretical predictions indicate that 1~2 plusmn 10% - MeV X-ray photons can be produced in a well-collimated beam. The expected photon flux is 10 photons per laser shot. Characterization of such a high-flux high energy X-ray beam is in progress. Quasi-monoenerg- - etic X-rays offer significant advantages for the detection of sensitive nuclear materials using techniques such as nuclear resonance fluorescence. A systematic effort is also in progress to further improve the characteristics of laser produced electron beams with regard to monochromaticity, divergence and stability and also permit easy tunability of the X-ray source. The design of a compact system capable of being deployed in the field will also be discussed as part of a long-term solution to the critical requirement for an efficient cargo-scanning system.

 

Rincon Third Order Cross-Correlator (TOCC)

Each Rincon is optimized for customer laser system and required range of measurements. The complete setup geometry, dimensions of non-linear crystals and some essential optics are all function of laser parameters and user-chosen tradeoffs between sensitivity, time resolution, time window, overall size etc.
We need the following information to set the tradeoffs and get all critical data necessary for the design which is optimized for your system:
1. What is wavelength of you laser system?
2. What is the repetition rate?
3. What is the normal pulse energy and beam diameter?
4. Is the laser pulse chirped?
5. What is the spectral bandwidth?
6. What is the pulsewidth?
7a. What is the expected (or estimated) contrast ratio as a function of delay from peak?
7b. What is the minimum necessary contrast ratio as a function of delay from peak?
8. What is beam quality (i.e. beam divergence relative to diffraction-limited one)?

Rincon third-order cross correlator (TOCC). Rincon has been specifically developed for measuring a wide array of output parameters from ultrafast laser systems including: contrast ratio of laser pulses, determining pulse pedestal, pre- and post-pulses, and amplified spontaneous emission (ASE) in femtosecond systems.

The third order cross-correlator Rincon has been specifically developed for measuring a wide array of output parameters from ultrafast laser systems including: contrast ratio of laser pulses, determining pulse pedestal, pre- and post-pulses, and amplified spontaneous emission (ASE) in femtosecond systems. It also provides information about the third-order cross-correlation function of pulse intensity on a femtosecond scale and can be used for alignment of high power femtosecond lasers. Cross-correlator includes opto-mechanical assembly and electronics with USB interface. System is easy to operate and includes a full set of user friendly software tools for data collection and analysis.

To request a quote for Rincon cross-correlator please e-mail sales@dmphotonics.com with detailed answers to the questions above.

Del Mar Photonics

 

Spectral phase interferometry for direct electric- field reconstruction (SPIDER) is one technique that can recover the spectral phase of an input pulse, without needing any reference pulse. SPIDER interferes two pulses which are separated in time and in frequency, and the resultant interferogram is read by a spectrometer. A thin etalon is used to pick off a portion of the input pulse and split it into two pulses delayed in time. The majority of the input pulse passes through the etalon and is stretched in time with a diffraction grating stretcher. The stretched pulse and the pulse pair off the etalon are recombined in a non-linear KDP crystal. Because the separation of the pulse pair is less than the pulse length of the stretched pulse the two pulses off the etalon will mix with different frequencies in the stretched pulse. This frequency difference is known as the spectral shear and is the frequency equivalent of a temporal delay. The resulting interferogram is then collected with a spectrometer. By performing a direct analysis of this interferogram, the spectral phase of the input pulse can be recovered. In addition, by independently measuring the pulse spectrum and performing a Fourier transform, the phase and intensity as a function of time can be retrieved. Thus the SPIDER technique offers a direct non-iterative measurement of the electric field of an ultrafast pulse.

 

Advantages
Low noise sensitivity
The interferogram measurements
taken with a 1-D spectrometer,
lowering cost, and increased simplicity.
Fast: interferogram reconstruction
calculations can be done in
milliseconds on a standard PC.
SPIDER setup involves no moving
parts during operation.
The acquisition of the experimental
trace is done in a single-shot.
Solid theoretical and conceptual
background.
Power supply from PC interface

 

Del Mar Photonics - Product brochures

Del Mar Photonics delivered Avoca SPIDER femtosecond measurement system and Rincon cross-correlator to University of Nebraska-Lincoln

Avoca SPIDER brochure - Avoca SPIDER manual - Avoca SPIDER software

Rincon brochure - Rincon manual - Rincon software