Integrated quantum optical phase sensor in thin film lithium niobate

Abstract

The quantum noise of light, attributed to the random arrival time of photons from a coherent light source, fundamentally limits optical phase sensors. An engineered source of squeezed states suppresses this noise and allows phase detection sensitivity beyond the quantum noise limit (QNL). We need ways to use quantum light within deployable quantum sensors. Here we present a photonic integrated circuit in thin-film lithium niobate that meets these requirements. We use the second-order nonlinearity to produce a squeezed state at the same frequency as the pump light and realize circuit control and sensing with electro-optics. Using 26.2 milliwatts of optical power, we measure (2.7 ± 0.2)% squeezing and apply it to increase the signal-to-noise ratio of phase measurement. We anticipate that photonic systems like this, which operate with low power and integrate all of the needed functionality on a single die, will open new opportunities for quantum optical sensing.

Emission Dipole and Pressure‐Driven Tunability of Second Harmonic Generation in vdWs Ferroelectric NbOI2

“…As a representative nonlinear optical phenomenon, second harmonic generation (SHG) effect exhibits the frequency doubling of the incident light wave, which is essential for nonlinear photonic and optoelectronic applications, such as optical switching, [1] light modulators, [2][3][4] and optical quantum information processing. [5][6][7] Traditional bulk materials with broken inversion symmetry, e.g., GaAs, [8,9] LiNbO 3 , [10,11] exhibit large second-order susceptibility. However, they suffer from irreducible volume, strict phase-matching conditions and lattice-match requirements, which limits their application in device integration.…”

Design and optimization of two-dimensional porous lithium niobate grating birefringent Bloch surface wave sensor with high sensitivity and quality factor

“…This discovery opens up new opportunities for quantum optical sensing. 33 In recent years, there has been significant progress in the manufacturing processes of photonic crystal sensors based on LiNbO 3 thin films. Tatiana et al reported the fabrication of LiNbO 3 thin films using block-shaped liquid nitrogen, followed by the production of one-dimensional photonic crystal (1D-PhC) beneath the LiNbO 3 thin film using commercial thin-film liquid nitrogen.…”

“…With an optical power of 26.2 mW, they measured a compression of (2.7±0.2)% and found that it could enhance the signal-to-noise ratio of phase measurements. This discovery opens up new opportunities for quantum optical sensing 33 . In recent years, there has been significant progress in the manufacturing processes of photonic crystal sensors based on LiNbO3 thin films.…”

Anisotropic Strain-Tailoring Nonlinear Optical Response in van der Waals NbOI2

“…Nonlinear optical (NLO) devices, which function on the basis of photon–photon (p-p) interactions within nonabsorbing media, play a vital role in stimulating advanced applications in modern on-chip photonic integrated circuits (PICs). − Second harmonic generation (SHG), a typical nonlinear parametric process describing the frequency doubling of incident light, lies at the core of various nonlinear photonic hardware, such as optical switches, , optical modulators, , and optical quantum information processors. , Typically, for a material with a specific lattice structure, the excitation amplitude of SHG is proportional to the nonvanishing components in the second-order susceptibility tensor, which is strictly constrained by the point group symmetry that the material belongs to . Bulk crystals with noncentrosymmetric lattice structures, for example, β barium borate (β-Ba­(BO 2 ) 2 ) and lithium niobate (LiNbO 3 ), have long been a central focus in developing SHG-related devices. , However, due to the inherently weak p-p interaction in these 3D classical media, achieving appreciable SHG response remains challenging within miniaturized interaction volumes under moderate light pumping, even though the strict phase-matching conditions are satisfied. , This inevitably hinders their integration in the state-of-the-art complementary metal-oxide-semiconductor (CMOS) compatible platform, which features continuous down-scaling with high power-efficiency. , …”

“…1−3 Second harmonic generation (SHG), a typical nonlinear parametric process describing the frequency doubling of incident light, lies at the core of various nonlinear photonic hardware, such as optical switches, 4,5 optical modulators, 6,7 and optical quantum information processors. 8,9 Typically, for a material with a specific lattice structure, the excitation amplitude of SHG is proportional to the nonvanishing components in the second-order susceptibility tensor, which is strictly constrained by the point group symmetry that the material belongs to. 10 Bulk crystals with noncentrosymmetric lattice structures, for example, β barium borate (β-Ba(BO 2 ) 2 ) and lithium niobate (LiNbO 3 ), have long been a central focus in developing SHG-related devices.…”