This talk will describe a technology that enables the utilization of second order nonlinearities, Chi(2) in monolithic semiconductors to be used as an optimal tool box for quantum optics. This approach uses dispersion engineering in Bragg reflection waveguides to harness parametric processes to produce non classical sources through down conversion [1-4]. These can also be realized in conjunction with concomitant dispersion and birefringence engineering in active devices such as semiconductor diode lasers [5-9]. On the classical front, the technology enables novel coherent light sources using frequency conversion in a self pumped chip-form factor. Novel sources for non-classical states of photons in this monolithic platform will be reviewed. These chip-based sources can afford the integration of other devices such as laser pump sources, power and polarization splitters, gates, cavities and much more. This platform essentially offers the capability of transferring current quantum optical setups from the optical table in a lab into a practical realm and even the market place. Also in this talk, some of the application that utilize the aforementioned sources will be discussed, including monolithic photonics architectures that enable deterministic splitting of entangled states of light will be discussed. In addition, sources for target detection and sensing protocols such as quantum illumination in integrated architectures will be also presented. The attributes of this platform offer unique opportunities in metrology applications where size, power, form-factor and space qualification are important factors.
This talk will describe a technology that enables the utilization of second order nonlinearities, Chi(2) in monolithic semiconductors to be used as an optimal tool box for quantum optics. This approach uses dispersion engineering in Bragg reflection waveguides to harness parametric processes to produce non classical sources through down conversion [1-4]. These can also be realized in conjunction with concomitant dispersion and birefringence engineering in active devices such as semiconductor diode lasers [5-9]. On the classical front, the technology enables novel coherent light sources using frequency conversion in a self pumped chip-form factor. Novel sources for non-classical states of photons in this monolithic platform will be reviewed. These chip-based sources can afford the integration of other devices such as laser pump sources, power and polarization splitters, gates, cavities and much more. This platform essentially offers the capability of transferring current quantum optical setups from the optical table in a lab into a practical realm and even the market place. Also in this talk, some of the application that utilize the aforementioned sources will be discussed, including monolithic photonics architectures that enable deterministic splitting of entangled states of light will be discussed. In addition, sources for target detection and sensing protocols such as quantum illumination in integrated architectures will be also presented. The attributes of this platform offer unique opportunities in metrology applications where size, power, form-factor and space qualification are important factors.
In this paper polarization and hybrid entangled source of light which were built using a fully on-chip battery-powered source of entangled photons will be discussed. These devices use monolithically integrated Bragg reflection waveguide laser diode (BRL) enabling high fidelity, record flux, compact photon pairs to be generated via a type-II intracavity phase-matching process. Furthermore, our turnkey source of entangled photon pairs operates at room temperature and does not require any external components or compensation. These qualities enable our chip to be optimal for highly scalable sources and remote operation. In addition, this talk will also discuss the first on-chip phase-sensitive amplifier utilizing χ(2) nonlinearity. These devices demonstrated the highest reported gain per unit length (devices with effective length ~ 0.1 mm providing gain exceeding 28 dB). Unique to χ(2) nonlinearity is that it also permits a pump that is spectrally far separated from the interacting signal and idler, allowing the highest reported sensitivity in any phase-sensitive amplifier (amplification capability down to an input of 0.005 photon per pulse). One of the main advantages of phase-sensitive amplifiers is their ability to reach a 0 dB noise figure, which enables many applications in quantum photonics.
Chip-scale integrated photonic circuits provide an attractive platform for the implementation of many quantum photonic technologies ranging from precise metrology to secure communication and quantum computation. In particular, silicon photonic platforms support micron-scale nonlinear optical sources of non-classical light which can be mass manufactured using the robust fabrication processes pioneered by the CMOS microelectronics industry. Integration of these quantum photonic sources with high-performance classical photonic devices on the same chip is required for truly scalable quantum information technologies. Integrated nonlinear resonators are investigated as sources of quantum mechanically correlated photon pair sources. An all-order dispersion engineering method is presented as a robust design synthesis for micoring sources. In addition, a novel concept of coupled mode dispersion compensation is proposed and demonstrated, providing significantly improved performance characteristics of resonant four-wave mixing sources. Next a photon pair source is demonstrated in a commercial CMOS microelectronics process opening the door to future integration of quantum photonics with electronic logic and control circuits. Classical nonlinear optical measurements of stimulated four-wave mixing are used for the first time to accurately predict the quantum correlations from the same device operating in the photon pair regime. Next the first demonstration of fully on-chip pump rejection is demonstrated with over 95 dB pump extinction improving the figures of merit from previous demonstrations by multiple orders of magnitude, including losses, detected pair rates and size. Finally, proposals for introducing novel degrees of freedom provided by an integrated platform are presented for further improving the performance of both photon pair and classical nonlinear optical sources.
Quantum states of photons such as entangled and single photons are indispensable components for applications in optical quantum information processing. Being able to generate and manipulate quantum states of photons on a chip is a crucial step towards realizing real-world quantum information processing systems such as an optical quantum computer. In this thesis, theoretical and experimental research was carried out for on-chip generation of quantum states of photons via the nonlinear process of spontaneous parametric down-conversion (SPDC), including polarization entangled photons, hyperentangled photons and heralded pure single photons. A majority of the study was based on III-V semiconductor AlGaAs, which could lead to monolithic integration of pump lasers and enable electrically pump sources operating at room temperature. The generation of cross-polarized entangled photons via a type-II SPDC in an AlGaAs Bragg reflection waveguide (BRW) was first investigated. The lack of material birefringence enables the direct generation of wavelength-multiplexed polarization entangled photons with a concurrence of at least 0.77 in a bandwidth of 95 nm. Second, a technique using concurrent type-0 and type-I processes on an AlGaAs chip to generate polarization entangled photon was developed. This technique allows the generation of both co-polarized and cross-polarized entangled photons on the same chip without the need of off-chip compensation, interferometer and bandpass filter. Third, a technique of generating hyperentangled photons on an AlGaAs chip was developed by utilizing spatial modes of different guiding mechanisms. High quality entanglement could be achieved with bandpass filtering of a few nanometers without off-chip phase compensation. Four, a generic technique using nonlinear photonic nanowires to engineer two-photon quantum states was proposed. Via dispersion engineering which controls the group velocity of each mode, maximally entangled polarization entangled photons and pure heralded single photons can be generated on-chip. Design examples were applied to III-V semiconductor and ferroelectric materials. Last, a strategy to enhance the bandwidths of wavelength conversion and SPDC spectrum was developed by tapering the waveguides. Combined with further integration of pump lasers, photonic circuits and detectors, the techniques developed in this thesis provides a viable route to achieve fully integrated generation and manipulations of photonic quantum qubits.
Integrated quantum photonics can realize and process optical entangled quantum states in highly compact, robust, and scalable chips thereby enabling chip scale implementations of long-distance quantum-secured communication, quantum-accelerated information processing, and non-classical metrology [1]. Notably, all previous on-chip entangled quantum photonic sources have relied on an external laser to excite nonlinear parametric processes, thereby making these systems overall non-reproducible, bulky, impractical, and thus unsuitable for out-of-lab use as well as production at large scale [2]. To date, the major challenge inhibiting a fully on-chip quantum light system is to integrate a stable, tunable laser together with a high rejection filter that eliminates laser sideband noise [3], [4] and a nonlinear parametric source of entangled photons. Fig. 1 A) laser-integrated photonic quantum light source of frequency-bin entangled photon states: an electrically pumped inp gain-section, i.e. A reflective semiconductor optical amplifier (rsoa) providing optical gain, is coupled to a si3n4 chip containing a three microring resonator (r1, r2, and r3) vernier filter and a mach-zehnder interferometer (mzi) with a sagnac loop mirror. B) measurements utilizing single photon detectors allowed to determine an smsr≈ 112 db, and an ase suppression of> 56 db. C) car for respective frequency pairs for an excitation power of 3.9 mw. D) density matrices of two-dimensional (qubit) and three-dimensional (qutrit) frequency-bin entangled states reconstructed via quantum state tomography (qst).
In quantum technology, entanglement is the key resource to perform experiments in quantum computing, quantum communication, quantum sensing and metrology. Generation, characterization and distribution of entanglement deterministically is still an active research area. In contemporary, probabilistic entanglement sources based on parametric down-conversion process remain the workhorse for experimental demonstrations and practical applications, despite their inherent limitations of on-demand entangled photon generation. Over the years, three main technological architectures have evolved for generating probabilistic entangled-photon source; bulk-optics, waveguides and integrated photonic chips, each comprising several distinct architectural approaches tailored to different applications. This review article talks about the state of the art in probabilistic entangled photon source, examining the advancement from free space bulk non-linear optics to fiber based waveguides and scalable photonic chips with their current limitations, presenting a road map for researchers to choose the most appropriate platform for their quantum photonic applications.
In quantum technology, entanglement is the key resource to perform experiments in quantum computing, quantum communication, quantum sensing and metrology. Generation, characterization and distribution of entanglement deterministically is still an active research area. In contemporary, probabilistic entanglement sources based on parametric down-conversion process remain the workhorse for experimental demonstrations and practical applications, despite their inherent limitations of on-demand entangled photon generation. Over the years, three main technological architectures have evolved for generating probabilistic entangled-photon source; bulk-optics, waveguides and integrated photonic chips, each comprising several distinct architectural approaches tailored to different applications. This review article talks about the state of the art in probabilistic entangled photon source, examining the advancement from free space bulk non-linear optics to fiber based waveguides and scalable photonic chips with their current limitations, presenting a road map for researchers to choose the most appropriate platform for their quantum photonic applications.