QUBIG is a world-leading expert in the field of light modulators and has dedicated significant effort to the development of high-performance electro-optic devices and matching driver electronics for precision manipulation of the Phase, Amplitude, and Polarization of individual photons with unprecedented accuracy. Our unique high-voltage technology and active mitigation of piezo-electric resonances allow us to reach rise times down to 5ns and up to 31-point accuracy for phase, polarization, and amplitude while keeping a very high transmission.

Quantum computing with light requires multi-photon interference and relies on indistinguishable single photons arriving simultaneously at the input ports of a photonic circuit. The isochronal photons distributed over N channels can be created by multiplexing a periodic train of photons from a single channel into multiple outputs.

QUBIG provides full systems for spatial demultiplexing of single photons based on our unique resonant electro-optic modulation technology. Our high-performance devices are compatible with single photon sources with repetition rates up to 160 MHz for demultiplexing into 2,4,8, and 16 channels [1,2].

REFERENCES

[1] XANADU Quantum computational advantage with a programmable photonic processor, Nature 606, 75–81 (2022)
[2] MPQ: Efficient generation of entangled multiphoton graph states from a single atom. Nature 608, 677–681 (2022)
[3] CNRS: Interfacing scalable photonic platforms: solid-state based multi-photon interference in a reconfigurable glass chip, Optica Vol. 6, Issue 12

Time-domain multiplexing offers a simpler hardware architecture for building fault-tolerant quantum computers. A small number of active components allows for the processing of a large number of modes. Key elements of this architecture are variable beam splitter (VBS) which consists of a programmable phase shifter and a programmable amplitude modulator [1].

QUBIG offers its unique programable VBS technology tailored for quantum computing applications.

QUBIG’s TWPM and matching drivers offer a unique dynamic tool for the control of a laser’s frequency relative to a reference. By comparing the sideband generated to the selected reference, it is possible to continuously tune the laser frequency up to 20 GHz away from the reference.

QUBIG SOL-Series can be used for three widely used frequency references: optical cavity, reference laser, and atomic transitions.

The SOL-system was developed to lock the high-frequency sideband onto an optical cavity. This is achieved by modulating the RF power to create additional low-frequency sidebands and generate a Pound–Drever–Hall error signal. The TWPM driving frequency provides a variable offset up to 20GHz between the cavity and the laser.

The MSL-series contains a built-in broadband phase modulator that generates sidebands onto the reference laser. A second laser is then locked to the reference sideband with the frequency offset being defined by the TWP’S driving frequency.

The TWPM series in combination with e.g. QUBIG’s spectroscopy modules for Rb (780nm and 420m) and Cs (852nm) allow to lock a sideband to a Doppler-free Saturated Spectroscopy (DFSS) signal providing a variable frequency offset to an absolute frequency reference.