Quantum Physics Applications

Spectra-Physics and New Focus are leaders in tunable lasers ideal for applications in the Atomic, Molecular, and Optical (AMO) physics field, including precision spectroscopy, atomic cooling, optical clocks, microcavity resonators, and other quantum applications.

Spectra Physics Lasers for Quantum Physics Applications

Quantum Encryption

Quantum entanglement is a physical phenomenon in which photon pairs are generated such that the quantum state of each photon cannot be described independently of the state of the other. It has many applications in quantum information theory including quantum cryptography. Ultrahigh quality factor (UHQ) microcavities have been emerging as a promising integrated platform for a wide range of applications from theoretical quantum physics to applied science. Pumped with a CW laser, multiple entangled photon pairs can be generated via optical parametric oscillation.

Quantum Computers

Quantum computers, tap-proof data transfer or highly sensitive sensors – quantum mechanical properties, such as superposition and entanglement, are fundamental to many of tomorrow’s technological systems. In the interdisciplinary core area of quantum information and technology, scientists at Ulm University investigate quantum physical phenomena in theory and by experimentation. The overall goal is to gain complete control over quantum systems. It is also about quantum physical effects in condensed matter, in nanostructures and in biological systems.

Novel sensors created by manipulation of individual atoms in diamonds
Figure 1. Novel sensors created by manipulation of individual atoms in diamonds
Novel sensors for use in cells are an important goal in research at Ulm University. To achieve this, scientists focus on the manipulation of individual atoms in diamonds. Prof. Fedor Jelezko, one of the world’s leading experts in controlling the smallest particles in solids - as demonstrated by the prestigious awards he has won - is involved in these research groups.

Atomic Clocks

The strontium optical lattice clock at JILA works by referencing an ultra-stable clock laser to laser-cooled and trapped strontium atoms. Strontium is one of nature’s highest-Q frequency references, with a quality factor of 1018. This clock takes advantage of the lower quantum projection noise of a manybody quantum system to achieve new records in clock precision, stability, and total systematic uncertainty. To prepare the atoms for precision spectroscopy, they are first laser-cooled using light from 461 nm blue diode lasers. Then, after a second red laser cooling stage, the atoms are loaded into an optical lattice, where they are trapped in standing waves of light. The clock laser is then used to perform coherent spectroscopy. The blue light is used again to measure the number of atoms in the ground and excited states via fluorescence. This allows us to measure the laser frequency against the atomic resonance.

Strontium Optical Lattice
Figure 2. Strontium Optical Lattice - Courtesy of Prof. Jun Ye, UC Boulder, JILA, NIST

Chip-Scale Optical Frequency Combs

Optical frequency combs are cornerstones of modern day metrology, precision spectroscopy, astronomical observations and ultrafast optics. State of the art methods to generate frequency combs in chip scale devices are based on Kerr and Raman nonlinearities in ultrahigh Q monolithic microresonators. Chee Wei Wong’s group at UCLA has demonstrated an electronic method to tune the dispersion of a silicon nitride microresonator used in comb formation, via a dual-layer ion gel gated graphene transistor fabricated on top of the cavity. This dispersion tuning is accomplished by coupling the gate-tunable optical conductivity of the graphene transistor to the intracavity field in the microresonator, while preserving cavity quality factors up to 106. With this method, charge-tunable primary comb lines from 2.3 terahertz to 7.2 terahertz, coherent Kerr frequency combs, controllable Cherenkov radiation and controllable soliton states, are all generated in a single microcavity.

A monolayer of organic molecules on the surface of
conventional UHQ microcavities allows these devices to
effectively generate frequency combs
Figure 3. A monolayer of organic molecules on the surface of conventional UHQ microcavities allows these devices to effectively generate frequency combs.

Atomic Cooling

ColdQuanta’s innovative BEC system is designed to streamline and simplify the production of ultracold atoms and BECs. At the heart of the system is the RuBECi® where rubidium atoms are cooled to temperatures of below 1 mK, trapped, and manipulated inside the vacuum cell. A New Focus Tapered Amplifier is used to provide ample power for laser cooling and manipulation of the atoms.

ColdQuanta’s innovative BEC system
Figure 4. ColdQuanta’s innovative BEC system

The New Focus Vortex™ Plus lasers and Tapered Amplifiers are employed in the JPL Cold Atoms Laboratory (CAL) science module now operating on the International Space Station (ISS), launched on May 21, 2018. The CAL science module will enable cold atom experiments in a microgravity environment with the intent to observe new quantum phenomena.

Quantum Application Lasers