Wes Campbell wins NSF CAREER award

Assistant Professor Wes Campbell has been selected by the National Science Foundation as a CAREER Awardee, based on his research proposal entitled "CAREER: Finessing Optical Frequency Combs for Direct Cooling and Trapping of Molecules."

The Faculty Early Career Development (CAREER) Program is a Foundation-wide activity that offers the National Science Foundation's most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations.

These are the details of Prof. Campbell's proposal.
While lasers are typically thought of as heating objects they shine upon, they have also come to be routinely used in scientific laboratories to make things extremely cold. Laser cooling is capable of refrigerating vapors of atoms to fractions of a degree above absolute zero, where their behavior is governed by quantum physics.

In the past three decades, scientists have used these cold atomic vapors as a scientific platform for learning about this quantum regime, and the field has given birth to applications such as atomic clocks and sensors. The chemicals that can be investigated in this way, however, are limited to only a handful by the laser colors available. Extending laser cooling to a broader array of atoms and molecules is desirable for learning about these species and how they interact at a level of detail not possible at room temperature.

The research team supported by this program will be studying the application of a different type of laser to cool these difficult species. These so-called "ultrafast" lasers can be made to emit an entire rainbow of colors at once, and this program will study how to finesse these sources into laser cooling a wider array of atoms and molecules. Successful extension of laser cooling to these species is expected to find use in the next generation of sensors, computers, and platforms for future science.

Direct laser cooling and trapping using optical frequency combs has the potential to extend laser cooling to more diverse species of atoms and molecules than are currently accessible. This potential arises due to their utility in creating many optical frequencies in parallel in parts of the optical spectrum where doing this with continuous-wave lasers is impractical, such as the deep UV.

The enhanced efficiency with which mode-locked lasers can drive two-photon transitions or be converted to desired wavelengths via nonlinear processes results in utilization of the full power in the comb even if only one tooth is used, making this process efficient. Specifically, researchers supported by this program will use picosecond mode-locked optical frequency combs for direct laser cooling and magneto-optical trapping of atoms on two-photon transitions (Rb, N) and single-photon laser cooling of diatomic molecules (SrH).

Time-dependent sweeps of the comb will also be investigated as a method for beam slowing and trap capture that would be applicable to a wider array of species than Zeeman slowing, such as diatomics. Development of a widely-applicable technique for cooling of molecules would have payoffs including the ability to address significant unknowns in the fields of dipolar quantum gases, quantum simulations, controlled chemistry, and quantum computing.

Prof. Campbell's website: http://campbellgroup.physics.ucla.edu/