Project Title: A versatile state-of-the-art laser source for Miami students

Long Title (if desired): Stable frequency-tunable single-mode laser source for frontier pedagogy and research with Miami students

Project Lead's Name: Samir Bali

Project Lead's Email: balis@MiamiOH.edu

Project Lead's Phone: 513-529-5635

Project Lead's Division: CAS

Primary Department: Physics

List Departments Benefiting or Affected by this proposal: Physics, and all departments whose students are required to take introductory physics courses PHY161/162/191/192 (i.e., Chemistry and Biochemistry, Biology, Botany, Zoology, Microbiology, all Engineering departments)

Estimated Number of Under Graduate students affected per year (should be number who will actually use solution, not just who is it available to): 730

Estimated Number of Graduate students affected per year (should be number who will actually use solution, not just who is it available to): 5

Describe the problem you are attempting to solve and your approach for solving that problem: Physics instructors enjoy a unique advantage over other STEM/Bio instructors in that they have many cool hands-on physics demonstrations they can have students do in class (e.g., let a suspended fifteen-pound bowling ball swing toward fellow-students' noses to demonstrate the conservation of energy, shoot ping pong balls through soda cans with an air-cannon to demonstrate momentum conservation, stand on a rotating turntable with arms wide-spread versus pulled-in figure-skater-style to demonstrate the conservation of angular momentum, the list goes on). Contrast this with the chemist's conundrum: I want to show this cool flashy chemical reaction but it involves fire/smoke/explosion/foul odor - how do I show it safely in class? Or the microbiologist's mind-muddler: How do I let my students examine for themselves this exciting microbe in action when I have only one or two microscopes that would do the job? Or the biologist's brain-baffler: How can my students see for themselves this important microscopic structure, say a protein, when the enabling equipment and reagents are only found in a lab setting? Youtube videos are nice, but no match for first-hand experiential learning.

THE PROBLEM, a.k.a. "the physicist's puzzle": Despite this unique advantage enjoyed by physics instructors, there exists a major problem in physics pedagogy: The perception gap in the students' minds between what is taught in class and what is new/current/cutting-edge in the field is large for physics - significantly larger than chemistry, biology, and engineering which, even at the introductory level, appear more modern and in-touch with today's problems/issues than physics. This is because the above­ described hands-on physics demos, cool though they may be, pertain to 17th-century physics. None of the equipment used for those demos would be found in a modem physics research lab.

Indeed, the demos themselves seem like "toy experiments" intended mostly for "fun". Students, especially the engineering majors, frequently gripe: "Ok, it's neat that a feather and a steel ball falls at the same rate in a vacuum, but we've known that since the 16th century. Anyway, for aircraft design, I need to know how to model air drag which you have neglected throughout the course! I'm afraid physics just doesn't apply to the real world!"

Here, then, is the demonstrator's dilemma: How to design and implement modern demonstrations that can effectively teach/train the student in what the main job of a physicist is - to not only explain the existing real world but also discover brave new worlds? Yes, physicists and engineers should indeed work together to understand the important, and beautiful, physics of air drag. But make no mistake: Galileo's true genius lay in ignoring air drag to reveal a subtle far-reaching (literally!) law of gravity that enabled humankind to understand celestial motion, discover black holes, and realistically contemplate space travel. Clearly, the challenge for the instructor is to educate the students about the brave new worlds currently being imagined and implemented by physicists. The traditional demos are frontiers, where all the excitement currently is in physics.

MY APPROACH: What are these new frontiers of physics where all the exciting research is currently happening? My approach is to focus on the quantum information frontier, which happens to be close to my research area. This is, without a doubt, a current leading frontier in physics as evidenced by the US government's enactment of the National Quantum Initiative Act in December 2018, which has committed $1.2 billion of federal funding for quantum information science research over an initial five-year period. A major component of the mandate is to develop a future quantum workforce in the country. Competition for the federal funding is intense with elite schools strategically investing internal resources in order to optimize their chances of receiving some of the money (e.g., Urbana­ Champaign is hiring 8 new faculty in this area over the next two years, with Northwestern, Chicago, and Wisconsin following suit...this is just in the Midwest; the Univ. of Arizona is hiring 13 new faculty in quantum information science!).

Below, I propose three specific projects by which Miami can make a vital contribution toward student training and research in quantum information science, thus positioning itself for viably competing with elite research-1 institutions for federal funding. The key is to acquire a state-of-the-art laser system that lies at the heart of quantum information science experimentation, from which the light output can be piped via optical fiber to all the different classrooms and instructional labs. Kreger Hall already has several fiber conduits in place for this purpose, which are yet to be used.

How would you describe the innovation and/or the significance of your project:

THE INNOVATION: Physics at the quantum frontier is about opening up entirely new and critically important technologies not yet harnessed by humankind. One major thrust is in the application of wave-particle duality to develop ultra-fast quantum computers. A second major thrust is in the application of quantum-entangled light­ and-matter-fields to enable ultra-dense data storage and processing. In both cases, there is a clear logical and pedagogical connection between traditional physics and frontier physics: Good old 17th-century concepts are pushed to extremes, seemingly morphing those simple concepts into completely counter-intuitive new ideas.

In the first case, consider the venerable principle of momentum conservation. But, instead of collisions between boring wooden balls, apply it to collisions between photons and atoms. By shining photons from all directions on an atom (much like throwing ping pong balls from all directions on a bowling ball) we can trap and slow the atoms down to temperatures a million times lower than the coldest cryogenic temperatures known to humankind. These ultra-cold atoms are the basic building blocks for a quantum computer - a current hot research topic because such a computer is predicted to be millions of times faster than the fastest computer built to date, namely electrons and atomic nuclei. Everyone knows that the tinier the object the harder it is to make it spin (because of the small lever­ arm) but still - electron spin and nuclear spin exist forming the basis for mature sensing technologies such as ESR (electron spin resonance) and NMR (nuclear magnetic resonance). Clearly near­ point particles such as electrons and nuclei can't really "spin" (the energy required would be infinite!), it's just that our limited intellect does not have English words to describe the quantum antics of sub­ atomic particles. By designing/implementing demonstrations and hands-on experimentation that clearly reveal the true nature of an electron and nuclear spin, students can be taught to understand what it means to produce ultra-slow light pulses in a specially­ prepared dilute gas - these are light pulses traveling at speeds less than 10 m/s (a factor 30 million times slower than the speed of light in the air; yes, Usain Bolt can outrun this light pulse) - a current hot topic of research in the young field of "quantum information processing" because scientists have way more time at their disposal (30 million times more) to densely encode/decode information on such slow­ traveling light pulses. Note that, much like a bullet train stopping to load/unload cargo at stations, the light pulses only slow down at the encoding/decoding stations but travel at the usual light-speed (186,000 miles/sec) in between, thus retaining the critically important feature of light as the fastest known carrier of information.

Below I describe three specific demonstrations and experiments enabled by the requested laser system. First-hand experiential learning of these demos/experiments will impart unique advantages to Miami students as they enter the STEM workforce. They would have seen/worked with novel subtle quantum phenomena which enable pushing new ideas to the extreme, beyond the wildest imaginings of people untouched by quantum information science.

For example, the idea of ultra-dense information storage using quantum techniques pushes to the extreme the field of big data: Should a giant database storing the genome of every human on Earth ever exist (certainly possible with the ever-decreasing cost of sequencing human genomes and the rise of genotyping services) - this would be the ultimate big data set considering that a single genome is equivalent to 6 billion bits. It has been shown by a collaborative group of MIT and Google researchers that only quantum information processing/storage techniques would permit searches for common patterns among different genes in a short period of time while still protecting individual privacy [Quantum support vector machine for big data classification, P. Rebentrost, et al, Physical Review Letters, 113, 130503 (2014)]. To be part of the new quantum workforce, as envisioned by the National Quantum Initiative, it would certainly serve Miami students well to have an inkling about these new-fangled quantum techniques.

WHAT EXACTLY DO WE PROPOSE TO DO AND WHAT'S THE SIGNIFICANCE? Light-atom interaction lies at the heart of both the above-described examples which showcase to the students frontier how this wave interacts with atoms. The single biggest obstacle to implementing these innovative ideas is procuring a single-mode laser source with the required exquisite frequency control and stability.

This proposal requests funds to purchase this laser system and pipe on demand its output via optical fiber to various classrooms and labs in Kreger Hall. The laser would be housed In my research lab to optimize the set-up process and daily maintenance from where the output would be split into the various fibers leading to the classrooms and instructional labs.

Below I describe three concrete innovative in-class and research activities that serve four distinct student groups totaling -730 students/year. Laser safety is addressed in all cases by the use of low light power (few milliwatts) along well-defined laser paths with negligible scatter, and the strategic placement of beam-blocks.

1. The "visualization and manipulation of the electromagnetic wavefront" demo/lab: Of the many natural manifestations of energy (heat, light, sound, mechanical, etc) the electromagnetic field (or light) is the one most harnessed by humankind in current technology (cellphones, lasers, GPS, microwave ovens, etc), yet the hardest to visualize. From both a pedagogical as "'811 as future employability point of view, it is imperative that our students be given the best possible opportunity to learn how to visualize and manipulate the oscillating electric and magnetic field vectors that form the light wave. Our department has two cutting-edge devices known as a spatial light modulator (SLM) and an electro-optic modulator (EOM) that allow us real-time control of the intensity, polarization, and phase at each point of the electromagnetic wave, in other words permitting us complete control of the electromagnetic wavefront.
   
   Both the SLM and the EOM require, as their input, light from a single­ mode stable light source. For three years we have tried, unsuccessfully in a classroom setting, to engineer an inexpensive home-built laser system for this purpose but the level of expert care/maintenance required by the home-built system is the sole obstacle that made our past endeavors logistically impractical. By contrast, the commercial laser system requested in this proposal would require minimal maintenance after the initial setup.
   
   Incorporating the commercial laser-enabled SLM and EOM devices into our undergraduate and graduate curriculum impacts the students significantly by allowing them a hands-on introduction to a vital cutting-edge tool. EOMs' are used in a wide array of research areas in optical science, such as rapid light switching, high-speed imaging, wideband data recording and more recently in adaptive optics for astronomy. SLMs' are used in diverse fields such as ultrafast laser pulse shaping, optical computing, optical tweezers, and microscopic laser surgery.
2. Actually spin: Our minds clutch onto a solar-system visualization, of a nucleus like a spinning sun surrounded by orbiting spinning electrons like planets, that is completely false. Nature's only currency is energy. Scientists have simply for convenience chosen to label as "spin states" some of the extremely small shifts in energy that have been observed between the allowed quantum states of sub-atomic particles. Quantum physics teaches us how to use light-atom interaction to easily observe the different spin states of the electron - known as "fine structure" of the atom. This is shown in many physics and chemistry sophomore labs across the nation including our PHY293 contemporary physics lab at Miami University.
   
   What typically does not show up however in the undergraduate and graduate curriculum is the demonstration/observation of the extremely, extremely small energy shifts attributed to the different spin states of the atomic nucleus - known as the "hyperfine structure" of the atom. There are two requirements for observing atomic hyperfine structure - first, a stable tunable laser system such as the model requested in this proposal, and second, an ingenious spectroscopic method known as "saturated absorption spectroscopy" (SAS) invented in 1972 by Arthur Schawlow (Nobel 1981) and his postdoc at the time Theodor Hansch (Nobel 2005). SAS is ingenious because it is robust, user-friendly, compact, portable, and inexpensive - not a problem to set up a demo in a large intro physics lecture hall, or have the sophomores set it up for themselves in PHY293 contemporary physics lab. Just as in the case of the SLM and EOM experiments in the previous demo/lab, the sole obstacle to observing nuclear spin states is that our home-built laser systems are simply not user-friendly/robust enough to permit reliable observation and measurement - a resolution of about 1 part-per­ billion of the optical wavelength is required.
   
   Why is it important for the quantum workforce to know how to measure and manipulate such small energy shifts between different nuclear spin states? Because it Is quantum superpositions of the electron spin-states and the nuclear-spin states that form the basis for the creation of ultra-slow light pulses which enable ultra-dense information storage.
3. The "coldest matter in the universe" demo/lab: The laser system would enable laser trapping of atoms, slowing them down to microKelvin temperatures (by comparison, the cryogenic temperature is defined as 4 Kelvin, the temperature where helium liquefies), where their speeds are slow enough that the students can see atoms moving with their naked eye. In addition to the laser, requirements are a small glass vacuum chamber full of Rubidium atoms, a small ion pump, and some optics that can be scrounged from existing materials in our advanced teaching lab. Everything except the laser can be set up on a portable breadboard. Just like the SAS setup for demonstrating nuclear spin, the actual trap where the atoms are confined is compact, portable, robust, and user-friendly. To shift the laser frequency such that the trap ceases to work. Note how this problem is neatly solved by simply having the laser sit in the safe confines of a research lab on a completely different floor.
   
   Still, this particular demo/lab is the most ambitious of the three suggested. We would know more in a couple of years. I see no reason why this idea of physically separating the laser source from the laser trap should not work, especially because the laser is inherently stable and quiet. With the home-built lasers, one has to continually monitor the trapped atom signal to know if the laser is stably frequency­ locked, and even so the laser loses lock killing the trap every few minutes.

The significance of the impact of the three demo/labs suggested above may further be gauged from the fact that these commercial laser­ enabled demonstrations/labs will be used to make a unique impact on four different student groups:

1. Both the SLM and EOM are compact and portable, hence ideally suited as a demonstration in our introductory physics PHY161/162/191/192 lecture classes. The PHY161-2 class typically has -300 students per year and the PHY191-2 class has -400 students. Under my supervision, a student volunteer from class will feed voltage-changes to the SLM, and show the class (via the classroom projector linked up to a PC) in real-time how to create interesting optical wavefronts such as, for instance, an optical "vortex", i.e., a beam that is twisted like a corkscrew around its axis of propagation. Similarly, students can feed voltage-changes to the EOM to explore in real-time how to control all three "knobs" that define a monochromatic electromagnetic wave at any point - the amplitude which represents the strength of the wave at that point, the polarization which represents the direction of the electric field vector at that point, and the phase which represents the propagation delay of the wave up to that point in units of the optical wavelength. The nuclear spin lab and the coldest matter lab will also be set up as demos in the PHY161/162/191/192 lecture classes. Observing nuclear spin states for themselves and watching atoms move with their bare eyes will convince them of the delicate yet powerful quantum resources nature has that are waiting to be revealed, and motivate them to consider joining the quantum workforce.
2. The SLM and EOM demo/lab, and the coldest matter lab, will be shown as a demonstration in our PHY293 contemporary physics lecture classes, similarly as in the intro physics classes described above. The PHY293 class for physics and engineering physics sophomores enrolls -20 students per year. What is exciting though is that the lab on the measurement of nuclear spin (hyperfine structure) can be added to the PHY293 class. This is exciting because the students in PHY293 already do a lab measuring the electron spin (fine structure). The plan is for them to work in groups of three or four, setting up the SAS scheme from scratch to measure the nuclear spin states. This is feasible because the laser stays stably locked at the concepts and is not difficult to set up.
3. I teach an advanced laser optics lecture/laboratory course PHY441/541 (3 weekly hour-long lectures and 1 two-hour laboratory session) entitled "Optics and Laser Physics" to seniors and Master-level students. This course is taught every other year and has an enrollment of typically 12-15 students with a 70/30 UG/G mix. All three labs discussed above will be projects for the students to work on, none will merely be a demo. In the lab, the students are divided into groups of three, resulting in four or five groups. Each group works on one experimental station. Four lecture periods will be used to teach the physics behind the SLM and EOM, and four lab sessions will be devoted to in-depth manipulation of the SLM and EOM. Because there is just one SLM (due to the cost) and three EOMs' we will rotate the SLM and EOM workstations between the various groups, in conjunction with another experiment involving home-built laser systems that require 4 weeks to complete. The nuclear spin/SAS measurement will be conducted in the same manner as in the PHY293 class. Setting up the coldest matter-in­ universe instructional lab will take some time. Students may work in larger groups of 4-5 to set up two setups, to begin with.
4. During the time the commercial laser system is not used to power the three projects described above for lecture demonstrations, or in the lecture/lab class, it will be used as a cutting-edge research device to help train, on an average, 2 undergraduate researchers and 1 graduate researcher per semester on producing highly efficient cold atom Brownian nanoratchets using ultra-slow light. Results obtained will be used in peer-reviewed journal articles with the students as co­ authors, and in grant proposals submitted by the Pl for federal funding such as NSF.

How will you assess the success of the project: The impact of the above-described three demos/labs on education at Miami will be assessed as below for the four different student bodies they are intended to serve. In all cases simple questions will be asked to assess if the students understood the logical connection between the traditional physics they knew before and the frontier physics they glimpsed as a result of these new demos/labs:

1. The -700 undergraduates in STEM and medical/health sciences taking introductory physics in PHY161-2 and PHY191-2, will be given an in-class 10-minute quiz on the next day of class which will test their understanding of the basics of how the SLM and EOM work, and what is meant by nuclear spin. They will use their intro-physics knowledge of momentum conservation to figure out how many photon collisions are required to slow an atom at room-temperature down to microKelvin temperatures.
2. A similar 10-minute quiz, but using more physics jargon, will be given to the 20 physics and engineering physics sophomores in the contemporary physics class PHY293. The impact on the students of the SAS lab to measure nuclear spin states (atomic hyperfine structure) will assessed by using a before and after survey. The current students in the laboratory will be asked questions (answer choices ranging from strongly agree to strongly disagree) such as you explain in detail the process of how SAS works to a high-school physics student. Questions of this nature are intended to delve into the students' understanding. The assessment given after the first year of implementation will be utilized to assess the impact of the project on student learning.
3. The impact on the 12-15 students taking the advanced laser optics lecture/laboratory class PHY441/541 will be assessed by using a before and after survey as described above.
4. The impact on the research conducted by the two undergraduates and one graduate student is easily assessed by noting the number of refereed publications co-authored and presentations given at prestigious conferences by these students that utilize the commercial laser system in any way. (This particular impact has a slightly longer-term scope: A period of two years ought to be given to collect data for this particular statistic.)

Financial Information

Total Amount Requested: $35,602.00

Budget Details: Quote is for the entire stable frequency-tunable laser system. The first 3 items form the laser source and optical amplifier system. The Faraday isolators (MFS780CA and MFS780) are light-valves to eliminate any deleterious back-reflections into the system. The electronics (DLC202 and LDD605) are for supplying current and temperature control. The Rb cell and Zeeman coil assembly are for locking the laser output frequency to an atomic hyperfine line. The last 4 items are for coupling the laser output out through a fiber. In our setup, we will then couple this output to various fibers leading to different classrooms and instructional labs in Kreger Hall. One fiber will also lead the laser output to our research experiment, thus ensuring the laser will be used at all times.

Is this a multi-year request: No

Please address how, if at all, this project aligns with University,  Divisional, Departmental or Center strategic goals: The proposal is in alignment with two important strategic goals, one national and the other university-wide:

1. THE NATIONAL QUANTUM INITIATIVE: The proposal is aligned with the US government's newly  enacted National Quantum Initiative  Act in December 2018, which has committed  $1.2 billion of  federal funding for quantum information science research over an initial fwe­ year period. A major component of the mandate is to develop a future quantum workforce in the country. Competition for the federal funding is intense with elite schools strategically investing internal resources in order to optimize their chances of receiving some of the money (e.g., Urbana-Champaign is hiring 8 new faculty in this area over the next two years, with Northwestern, Chicago, and Wisconsin following suit...this is just in the Midwest; the  Univ. of  Arizona is hiring 13 new faculty in quantum information science!). Three specific projects are proposed by which Miami can make a vital contribution toward student training and  research  in  quantum  information science, thus positioning itself for viably competing with elite research-1 institutions for federal funding.
2. MIAMI UNIVERSITY'S PRIORITY ON BIG DATA: First-hand experiential learning of the three specific demos/experiments proposed here will impart unique advantages to Miami students as they enter the STEM workforce. They would have seen/worked with novel subtle quantum phenomena which enable pushing new ideas to the extreme, beyond the wildest imaginings of people untouched by quantum information science. For example, the idea of ultra-dense information storage using quantum techniques pushes to the extreme the field of big data: Should a giant database storing the genome of every human on Earth ever exist (certainly possible with the ever-decreasing cost of sequencing human genomes and the rise of genotyping services) -this would be the ultimate big data set considering that a single genome is equivalent to 6 billion bits. It has been shown by a collaborative group of MIT and Google  researchers that only quantum information processing/storage techniques would permit searches for common patterns among different genes in a short period of time while still protecting individual privacy [Quantum support vector machine for big data classification, P.  Rebentrost, et al, Physical Review Letters, 113, 130503 (2014)]. To be part of the new quantum workforce, as envisioned by the National Quantum Initiative, it would certainly serve Miami students well to have an inkling about these novel cutting-edge quantum techniques.