Summary:
UCLA Researchers in the Department of Electrical and Computer Engineering have developed an innovative technique that can tailor spectral-temporal optical pulses for electron sources, advanced spectroscopic techniques, material processing, and proton-based cancer therapies.
Background:
Optical laser pulses with short wavelength and picosecond duration are useful for a wide array of applications including spectroscopy, proton therapy, material processing and photoinjection. However, it is difficult to modulate the shape of picosecond optical laser pulses due to their narrow spectral bandwidth and brief temporal duration. Additionally, current shaping methods rely either on spectral or temporal techniques, leading to a suboptimal upconversion and often lead to phase distortion and intensity fluctuation. Such characteristics impose a challenge on utilizing standard methods such as direct electronic modulation for optical pulse shaping. In order to tailor optical pulses for emerging applications such as proton therapy and spectroscopy, there is a critical need to efficiently modulate the shape of spectral-temporal optical pulses and avoid current shaping limitations.
Innovation:
Professor Carbajo and his team of UCLA, Stanford, and SLAC National Accelerator Laboratory researchers have developed an innovative technique that can programmably shape optical pulses in the spectral and temporal domain. The method, which the inventors have termed dispersion controlled nonlinear shaping (DCNS), can directly up- or down-convert optical pulses at very high efficiencies and beam quality while controlling the temporal intensity shape of picosecond-long pulses from femtosecond pulses. DCNS allows researchers to generate favorable pulse shapes for their specified applications with an increased energy efficiency of 40%. By overcoming current suboptimal shaping techniques, the inventors present a method that could enable further exploitation of pulse shaping for application in a wide array of disciplines including proton-based cancer therapies and material processing.
Potential Applications:
• Proton-based cancer therapies
• Spectroscopy
• Material processing
• Photoinjector-based electron sources
• Particle accelerators
Advantages:
• Improved electron emittance across broad range of bunch lengths
• Improved beam brightness
• Avoids phase distortion and intensity fluctuations
• No major configuration changes needed
• Conversion efficiencies greater than 40%
Development to Date:
The invention has been fully reduced to practice in a laboratory setting.
Related Papers: Lemons, R., Neveu, N., Duris, J., Marinelli, A., Durfee, C., & Carbajo, S. (2022). Temporal shaping of narrow-band picosecond pulses via noncolinear sum-frequency mixing of dispersion-controlled pulses. Physical Review Accelerators and Beams, 25(1). https://doi.org/10.1103/PhysRevAccelBeams.25.013401
Reference: UCLA Case No. 2022-286
Lead Inventor: Sergio Carbajo Garcia