Abstract Broadband on-chip optical frequency combs (OFCs) are important for expanding the functionality of photonic integrated circuits. Here, we demonstrate a huge local nonlinearity enhancement using graphene. A waveguide is decorated with graphene by precisely manipulating graphene’s area and position. Our approach simultaneously achieves both an extremely efficient supercontinuum ultra-short pulse generation. With our graphene-decorated silicon (G-SWG), have achieved enhanced spectral...

Acoustically induced dressed states of long-lived erbium ions in a crystal are demonstrated. These formed by rapid modulation two-level systems via strain surface acoustic waves whose frequencies exceed the optical linewidth ion ensemble. Multiple sidebands and reduction their intensities appearing near evidence strong interaction between ions. This development allows for on-chip control paves way to highly coherent hybrid quantum with telecom photons, phonons, electrons.

Monolayer graphene absorbs 2.3 percent of the incident visible light. This “small” absorption has been used to emphasize visual transparency graphene, but it in fact means that multilayer a sizable fraction light, which causes non-negligible fluorescence. In this paper, we formulate light emission properties composed tens hundreds layers using transfer matrix method and confirm method’s validity experimentally. We quantitatively explain measured contrasts on SiO2/Si substrates find...

Low-noise millimetre-wave signals are valuable for digital sampling systems, arbitrary waveform generation ultra-wideband communications, and coherent radar systems. However, the phase noise of widely used conventional signal generators (SGs) will increase as frequency increases. Our goal has been to improve commercially available SGs so that they provide a low-phase-noise with assistance from an electro-optics-modulator-based optical comb (EOM-OFC). Here, we show can be greatly reduced by...

We propose a method of supercontinuum light generation enhanced by multimode excitation in precisely dispersion-engineered deuterated SiN (SiN:D) waveguide. Although regularly designed SiN-based nonlinear optical waveguide exhibits anomalous dispersion with the fundamental and first-order operation, center-symmetric pumping at input edge has so far inhibited full potential nonlinearity materials. On basis numerical analysis simulation for SiN:D waveguide, we intentionally applied spatial...

We demonstrate that a 2f-to-3f self-referencing interferometer (SRI) becomes useful tool for stabilizing carrier-envelope offset frequency of an Er-doped fiber laser. A dual-pitch periodically poled lithium niobate (PPLN) ridge waveguide, consisting two monolithically integrated segments with different quasi-phase matching pitch sizes, allows us to generate third-harmonic light high efficiency. By using this device, we obtain 45-dB signal-to-noise ratio in 100-kHz bandwidth heterodyne beat...

We have achieved the simultaneous generation of a 2.6-octave-wide supercontinuum (SC) spectrum over 400-2500 nm and third-harmonic light solely by dispersion-controlled silicon-nitride waveguide (SiNW). To increase visible intensity SC component, we fabricated low-loss 5-mm-long deuterated SiNWs with spot-size converters low-temperature deposition. succeeded in measuring carrier-envelope-offset (CEO) signal 34-dB signal-to-noise ratio because this short SiNW provides large temporal overlap...

We report a new transport feature in GaAs lateral double quantum dot that emerges for magnetic-field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP). This DNP signal appears the Coulomb blockade regime by virtue of finite interdot tunnel coupling originates from crossing between ground levels triplet singlet extensively used manipulations pulsed-gate experiments. The dependence current level is suggestive unbalanced two dots, which opens up possibility controlling...

We demonstrate on-chip octave-spanning supercontinuum (SC) generation with a Si-wire waveguide (SWG). precisely controlled the SWG width so that group velocity becomes flat over wide wavelength range. By adjusting length, we could reduce optical losses due to two-photon absorption and pulse propagation. In addition, for efficient coupling between laser waveguide, fabricated two-step inverse taper at both ends of SWG. Using 600-nm-wide SWG, were able generate broadband SC spectrum wavelengths...

Abstract Graphene absorbs light in accordance with the fine-structure constant α ≃ 1/137. The value is universal sense that it unrelated to material parameters but solely related elementary charge, which a fundamental governing coupling of and matter. A new universality governed only by has yet be discovered graphene optics. However, since dimensionless quantity, can anticipated reciprocal appears as characteristic number layers absorptance an N -layer graphene. Here, we report this 2/ π ....

We report the stabilization of carrier-envelope offset (CEO) frequency an Er-doped fiber laser with a collinear 2f-to-3f self-referencing interferometer. The interferometer is implemented by dual-pitch periodically poled lithium niobate ridge waveguide two different quasi-phase matching pitch sizes. obtain 52-dB signal-to-noise ratio in 100-kHz resolution bandwidth heterodyne beat signal, which sufficient for stabilization. also demonstrate that geometry robust against environmental...

A midfringe locked interferometer with differential detection is proposed for non-contact optical sound measurement, and the equivalent noise level of approximately 0 dB SPL/Hz achieved. The method 30 lower than that a very recent laser Doppler vibrometer close to quarter-inch measurement microphone. locking stabilizes against slow environmental fluctuations enables acoustic signal directly from intensity. eliminates intensity noise, which dominant source in interferometers. constructed...

Landau-Zener (LZ) transition has received renewed interest as an alternative approach to control single-qubit states. An LZ occurs when a system passes through avoided crossing that arises from quantum mechanical coupling of two levels, taking the coherent superposition Then, multiple transitions induce interference known Landau-Zener-Stückelberg (LZS) whose amplitude strongly depends on velocity or adiabaticity passage. Here, we study roles and LZS in charge oscillations one-electron...

We study low-frequency noise in current passing through quantum point contacts fabricated from several GaAs/AlGaAs heterostructures with different layer structures and fabrication processes. In contrast to previous reports, there is no gate-dependent random telegraph (RTN) originating tunneling a Schottky barrier devices using the standard low-damage process. Gate-dependent RTN appears only high-damage process that induces charge trap sites. show insertion of AlAs/GaAs superlattices AlGaAs...

Silicon nitride (SiN) films formed by liquid-source chemical vapor deposition (LSCVD) were analyzed for photonic applications. While this technique SiN has strengths in its low reaction temperature (>80 °C) and fast rate (>50 nm/min), the material properties, such as composition, bond, optical absorption bands waveguides, have not been studied quantitatively. Hence, we probed to understand characteristics ultraviolet-to-midinfrared ellipsometry, on-chip waveguide spectrometry,...

Abstract A simpler and more accurate measurement of absolute optical frequencies (AOFs) is very important for communications navigation systems. To date, an reference has been needed measuring AOFs with twelve-digit accuracy because the difficulty in them directly. Here, we focus on electro-optics-modulation comb that can bridge vast frequency gap between photonics electronics. We demonstrate unprecedented method directly measure to twelve digits RF counter by simply delivering a...

Abstract The generation of a 24‐fs fibre‐coupled electro‐optic‐modulation (EO) comb at 1.5 μm with 25‐GHz repetition rate, which is the shortest pulse, demonstrated. authors also generated 2/3‐octave spanning supercontinuum spectrum using precise dispersion‐controlled silicon nitride waveguides. This method can open new horizons to generate compact and robust carrier‐envelope‐offset‐locked EO comb.

Acousto-optic measurement of sound (AOMoS) has been widely utilized in various acoustic studies owing to its noninvasive nature. However, the presence significant noise often degrades acousto-optic signals and thus hinders promising applications. This is partly because characteristics noises AOMoS have not fully clarified, which prevents us from adequately predicting controlling them. To address this challenge, we theoretically experimentally investigate three specific AOMoS: optical...

The pulse energy for stabilizing the carrier-envelop offset frequency of an Er-doped fiber laser was reduced by a dual-pitch (DP-) periodically poled lithium niobate (PPLN) ridge waveguide implemented in 2f-to-3f self-referencing interferometer (SRI). requirement less than half that single-pitch PPLN f-to-2f SRI. We also found environmental noise could be adjusting stabilization with DP-PPLN waveguide, as estimated from phase out-of-loop interferometer.

The generation of second‐ and third‐harmonic light with single‐ dual‐pitch periodically poled lithium niobate ridge waveguides for achieving a carrier‐envelope‐offset‐locked frequency comb low pulse energy is investigated. wavelengths both the converted by short‐ long‐wavelength components supercontinuum spectra are precisely adjusted selecting appropriate pitch size controlling temperature devices. output powers 9.1 4.8 µW, respectively, when using 2/3‐octave‐wide generated 1.2 nJ laser at...

Monolayer graphene absorbs 2.3 percent of the incident visible light. This “small” absorption has been used to emphasize visual transparency graphene, but it in fact means that multilayer a sizable fraction light, which causes non-negligible fluorescence. In this paper, we formulate light emission properties composed tens hundreds layers using transfer matrix method and confirm method’s validity experimentally. We could quantitatively explain measured contrasts on SiO2/Si substrates found...

We demonstrated a highly efficient optical memory operation using an atomic frequency comb (AFC) created from spectrally flattened with isotopically pure 167 Er 3+ :Y 2 SiO 5 crystal under zero magnetic field. Compared standard AFC creation methods such as pulse train method, our called transfer can create broadband and high-efficiency at lower power less effort. This technique make significant improvement in the quality of AFCs crystals doped low concentrations rare-earth ions.

We performed time-resolved reflectivity measurements and characterized the time-varying oscillations of longitudinal acoustic phonons in InGaAsP multiple quantum wells (MQWs) by asynchronous optical sampling with Er-doped fiber lasers. Oscillations ranging from a few tens to hundred gigahertz were observed, which induced forward backward Raman scattering Brillouin first zone-folded phonon modes. To investigate dynamics each mode for various pump-probe time delays, we analyzed experimental...