Scholarly Publications - Physics
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Item Open Access Exploring localized ENZ resonances and their role in superscattering, wideband invisibility, and tunable scattering(Nature Publishing Group, 2024-01-18) Serebryannikov, Andriy E.; Özbay, EkmelWhile the role and manifestations of the localized surface plasmon resonances (LSPRs) in anomalous scattering, like superscattering and invisibility, are quite well explored, the existence, appearance, and possible contribution of localized epsilon-near-zero (ENZ) resonances still invoke careful exploration. In this paper, that is done along with a comparison of the resonances of two types in the case of thin-wall cylinders made of lossy and loss-compensated dispersive materials. It is shown that the localized ENZ resonances exist and appear very close to the zero-permittivity regime, i.e., at near-zero but yet negative permittivity that is similar to the ENZ modes in thin planar films. Near- and far-field characteristics of the superscattering modes are investigated. The results indicate that the scattering regimes arising due to LSPRs and localized ENZ resonances are distinguishable in terms of the basic field features inside and around the scatterer and differ in their contribution to the resulting scattering mechanism, e.g., in terms of the occupied frequency and permittivity ranges as well as the sensitivity to the wall thickness variations. When the losses are either weak or tend to zero due to the doping with gain enabling impurities, the sharp peaks of the scattering cross-section that are yielded by the resonances can be said to be embedded into the otherwise wide invisibility range. In the case of lossy material, a wide and continuous invisibility range is shown to appear not only due to a small total volume of the scatterer in the nonresonant regime, but also because high-Q superscattering modes are suppressed by the losses. For numerical demonstration, indium antimonide, a natural lossy material, and a hypothetical, properly doped material with the same real part of the permittivity but lower or zero losses are considered. In the latter case, variations of permittivity with a control parameter can be adjusted in such a way that transitions from one superscattering mode to another can be achieved. In turn, transition from the strong-scattering to the invisibility regime is possible even for the original lossy material. The basic properties of the studied superscattering modes may be replicable in artificial structures comprising natural low-loss materials.Item Open Access A novel method to eliminate the symmetry dependence of fiber coils for shupe mitigation(Nature Publishing Group, 2024-04-20) Şenol, Tuğba Andaç; Akçaalan, Önder; Yertutanol, Aylin; Özbay, EkmelIt is a well-known fact that interferometric fiber optic gyroscopes (IFOGs) are easily distorted by thermal effects and distortion results in the degradation of the performance of these sensors. Changing the fiber coil geometry, increasing the winding symmetry, adding fiber buffer layers around the fiber coil, using different modulation methods for multifunctional integrated optic chips, and using special types of fibers, such as photonic crystal fibers, are some alternative solutions for preventing this degradation. This paper, theoretically and experimentally, investigates not only how different types of fiber coil winding methods behave under different rates of temperature change but also presents a novel method, to the best of our knowledge, to eliminate the Shupe effect, without violating the simplest IFOG scheme. This method rules out the importance of the winding symmetry epochally and the need of any extra treatment for the fiber coil to increase the thermal performance of the system. Regardless of the symmetry of the fiber coil winding, the rate error due to the Shupe effect can be reduced to about ±0.05◦/ h for any rate of temperature change with this new method according to the experimental results.Item Open Access Few-layer bifunctional metasurfaces enabling asymmetric and symmetric polarization-plane rotation at the subwavelength scale(Nature Publishing Group, 2024-06-13) Gökkavas, Mutlu; Gökkavas, Tamara Funda Gündoğdu; Özbay, Ekmel; Serebryannikov, Andriy E.We introduce and numerically validate the concept of few-layer bifunctional metasurfaces comprising two arrays of quasiplanar subwavelength resonators and a middle grid (array of rectangular holes) that offer both symmetric and asymmetric transmissions connected, respectively, with symmetric and asymmetric polarization-plane rotation functionalities. The proposed structures are thinner than λ/7 and free of diffractions. Usually, the structure’s symmetry or asymmetry, i.e. unbroken or broken spatial inversion symmetries, are considered for metasurfaces as prerequisites of the capability of symmetric or asymmetric conversion of linearly polarized waves, respectively. Due to the achieved adjustment of the resonances enabling the rotation of the polarization plane simultaneously for both orthogonal polarizations of the incident wave, the symmetric polarization-plane rotation functionality can be obtained within one subwavelength band, whereas the asymmetric polarization-plane rotation functionality associated with the asymmetric transmission is obtained within another subwavelength band. This combination of the functionalities in one subdiffraction structure is possible due to the optimal choice of the grid parameters, since they may strongly affect the coupling between the two resonator arrays. Although normal incidence is required for the targeted bifunctionality, the variations of the incidence angle can also be exploited for the enrichment of the overall functional capability. Variations of the polarization angle give another important degree of freedom. The connection between the polarization-angle dependence of cross-polarized transmission and capability of symmetric and asymmetric polarization-plane rotation functionalities is highlighted. The feasible designs of the bifunctional metasurfaces are discussed.Item Open Access Lithography-free tunable Fano resonator(Institute of Electrical and Electronics Engineers, 2024-09-30) Omam, Zahra Rahimian; Khalichi, Bahram; Osgouei, Ataollah Kalantari; Ghobadi, Amir; Khalily, Mohsen; Özbay, EkmelThis paper presents a lithography-free thermally tunable Fano resonator obtained by strong coupling between the narrowband and broadband resonators. The unique optical phonon response of the Dolomite (DLM) thin film and the phase-change material (PCM) of vanadium dioxide (VO2) are utilized to design such a Fano resonator. The findings of this study can have multiple applications, ranging from biosensing and gas-sensing to the modulation of thermal emission.Item Open Access A polarization-dependent reflective color filter with grating-based Sb2S3 phase-change material(Institute of Electrical and Electronics Engineers, 2024-09-30) Omam, Zahra Rahimian; Khalichi, Bahram; Osgouei, Ataollah Kalantari; Ghobadi, Amir; Khalily, Mohsen; Özbay, EkmelThis paper presents a reflective tunable color filter based on employing an antimony trisulfide (Sb2S3) grating structure. The design generates two different colors when illuminated by either one of two orthogonally polarized incident lights. Moreover, by adjusting the phase of the material, the resonances can be tuned, enabling the generation of different colors. This design offers a simple platform capable of generating four distinct colors across the visible spectrum.Item Open Access Active control of Fano resonance with phase-change-based metasurface(Institute of Electrical and Electronics Engineers, 2024-09-30) Omam, Zahra Rahimian; Khalichi, Bahram; Osgouei, Ataollah Kalantari; Ghobadi, Amir; Khalily, Mohsen; Özbay, EkmelThis paper presents a phase-change-based metasurface absorber that can control the excitation of Fano resonance with temperature variations. The proposed thermally tunable metasurface-based configuration is designed based on strong coupling between the narrowband (discrete state) and broadband (continuum state) absorbers, leading to an excitation of Fano resonance within the infrared region.Item Open Access A highly survivable X-band low noise amplifier based on GaN HEMT technology and impact of pulse width on recovery time(John Wiley and Sons Inc, 2024-09-20) Nawaz, Muhammad Imran; Zafar, Salahuddin; Akoğlu, Büşra Çankaya; Çağlar, Gizem Tendürüs; Hannan, Abdullah; Urfalı, Emirhan; Aras, Erdem; Özbay,EkmelGaN high electron mobility transistor (HEMT)-based low noise amplifiers (LNAs) are an integral part of microwave receiver systems to enhance signal-to-noise ratio (SNR). The noise of LNA itself becomes critical for systems requiring high SNR, such as imaging and satellite communication systems. This paper discusses the design of a three-stage LNA operating at the X-band in the frequency range of 8.0-12.0 GHz. The amplifier's design and small signal, noise, and linearity characterizations are discussed. Stagewise analysis for gain, noise figure (NF), and matching network losses at the design stage results in achieving promising results. The proposed LNA provides a gain of 23.2 dB with +/- 1.0 $\pm \ 1.0$ dB gain ripple. Its NF is below 1.5 dB, output power at 1 dB gain compression is 16.4 dBm, and third-order intercept point is 24.7 dBm at 10 GHz. LNA's survivability is validated to input stress as high as 42 dBm. This LNA is the best reported NF and survivability combination in the 8.0-12.0-GHz frequency range. The reverse recovery time of LNA is measured under two different pulse conditions, and it has been shown that LNA has better recovery times for lower pulse width signals. This LNA finds its applications in radars and satellite communication systems.Item Open Access HfO₂-based memristors for gamma-ray detection: An experimental and computational investigation(IEEE, 2024-02-01) Saylan, Sueda; Hitt, George Wesley; Jaoude, Maguy Abi; Mohammad, BakerIn this work, we present a memristor with a thin film (~100-nm-thick) of a high-atomic-number material in a Cu/HfO2/$\text{p}^{+}$-Si stack to detect gamma-ray irradiation doses as low as ~30 mGy. The device leverages the unique properties of memristors, which exhibit a change in the resistance state upon applying an external electrical bias. This characteristic makes them well suited for dosimetry applications as the radiation exposure induces a change in the programming voltage ${V}_{{\text {SET}}}$. Our experiments reveal, on average, a 60% or more decrease in ${V}_{{\text {SET}}}$ in response to gamma-ray irradiation, covering a dose range of 30–850 mGy. These results highlight the potential of memristive sensing as a valuable tool for monitoring radiation exposure in space, safeguarding both individuals and electronics from its detrimental effects. In addition to the experimental findings, coupled radiation transport and radiation damage cascade simulations performed provide energy deposition, ionization, and defect distributions in the stack, yielding new insights into the device’s response to ionizing radiation. This combined approach aims at enhancing our understanding of the underlying processes and further optimizing the memristive sensing capability for radiation monitoring in space missions.Item Open Access Investigation of SiNx: Surface passivation impact on InAsP/InGaAs e-SWIR photodiodes(IEEE, 2024-01-01) Satılmış, Mert; Gezgin, İrfan Alp; Tok, Cağrı; Keleş, Habibe; Kolkowski, Walery; Pasternak, Iwona; Oğuz, Fikri; Strupinski, Wlodek; Özbay, EkmelIn this study, we investigate the deposition of SiNx:H thin films using the inductively coupled plasma chemical vapor deposition (ICPCVD) method with NH3/SiH4 ratios ranging from 1.3 to 25. The impacts of these variations on extended short-wave infrared region (e-SWIR) photodiodes (PDs) were characterized through stress, reflectance, photoresponse, and dark current modeling techniques. It was observed that an increase in H content leads to a decrease in both the refractive index and stress. To reveal the effects of H content on the bond numbers of N-H, Si-H, and Si-N within SiNx:H, FTIR measurements were conducted. This allowed us to investigate the K − trap centers depending on the change in NH3/SiH4 ratios. The influence of H content on the passivation layer was examined through dark current modeling and PD performance evaluations. The optimized passivation layer underscores that the dark current of the PD is G-R limited, with diffusion current emerging as the dominant component at high temperatures. Additionally, the PD performance was enhanced with optimized passivation, achieving a higher photo-to-dark current ratio, a responsivity of 0.97 A/W at $2~\mu$ m, an external quantum efficiency (E.Q.E.) peak of 70.8% at $1.6~\mu$ m, and a dark current density of $120~\mu$ A/cm2 at 300 K under a 100 mV reverse bias voltage.Item Embargo Rearrangement and breakup amplitudes from the solution of Faddeev-AGS equations by pseudo-state discretization of the two-particle continuum(Elsevier BV, 2024-08-08) Kuruoğlu, Zeki CemalThe AGS equations for rearrangement transition operators in the three-particle problem are turned into a set of effective multi-channel two-body equations using the pseudo-state discretization of the two-particle resolvent. The resulting effective equations are LS-type integral equations in the spectator degrees of freedom, much like the LS equations of multichannel inelastic scattering. In particular, the effective potential matrix is real, energy-independent and non-singular, while the propagator matrix has only simple poles. Difficulties associated with the moving singularities of the effective potential matrix in the usual separable-T approach to AGS equations are avoided. After regularization of the kernel via subtraction procedures well known from two-particle scattering, the set of coupled LS-type equations in the spectator momenta are solved rather straightforwardly by the Nyström method. Solutions of effective two-body equations are then used to calculate the breakup amplitudes using the well-known relationship between rearrangement and breakup amplitudes. Calculations using a local momentum-space basis on a benchmark model of the n+d collision show that rather accurate results for elastic and breakup amplitudes can be obtained with rather small bases.Item Open Access Tattoo-like multi-color physically unclonable functions(Wiley-VCH Verlag GmbH & Co. KGaA, 2023-12-07) Kiremitler, N. B.; Esidir, A.; Drake, G. A.; Yazıcı, A. F.; Şahin, F.; Torun, İ.; Kalay, M.; Kelestemur, Y.; Demir, Hilmi Volkan; Shim, M.; Mutlugün, Evren; Önses, Mustafa SerdarAdvanced anti-counterfeiting and authentication approaches are in urgent need of the rapidly digitizing society. Physically unclonable functions (PUFs)attract significant attention as a new-generation security primitive. The challenge is design and generation of multi-color PUFs that can be universally applicable to objects of varied composition, geometry, and rigidity. Here in, tattoo-like multi-color fluorescent PUFs are proposed and demonstrated. Multi-channel optical responses are created by electro spraying of polymers that contain semiconductor nanocrystals with precisely defined photoluminescence. The universality of this approach enables the use of dot and dot-in-rod geometries with unique optical characteristics. The fabricated multi-color PUFs are then transferred to a target object by using a temporary tattoo approach. Digitized keys generated from the red, green and blue fluorescence channels facilitate large encoding capacity and rapid authentication. Feature matching algorithms complement the authentication by direct image comparison, effectively alleviating constraints associated with imaging conditions. The strategy that paves the way for the development of practical, cost-effective, and secure anticounterfeiting systems is presented.Item Open Access Laser lithography of monolithically-integrated multi-level microchannels in silicon(Wiley-VCH Verlag GmbH & Co. KGaA, 2024-02-27) Tauseef, Muhammad Ahsan; Asgari Sabet, Rana; Tokel, OnurThe trend toward ever-increased speeds for microelectronics is challenged bythe emergence of heat-wall, leading to the faltering of Moore’s Law. Apotential solution may be integrating microfluidic channels into silicon (Si), todeliver controlled amounts of cooling fluid and regulate hot spots. Suchmeandering microfluidic channels within other transparent materials alreadyplayed significant roles, including in biomedical and sensor applications;however, analogous channel architectures do not exist in Si. Here, a novelmethod is proposed to fabricate buried microchannel arrays monolithicallyintegrated into Si, without altering the wafer surface. A two-step,laser-assisted subtractive removal method is exploited, enabling fully-buriedmulti-level architectures, with control on the channel port geometry, depth,curvature, and aspect ratio. The selective removal rate is 750 μm per h perchannel, and the channel inner-wall roughness is 230 nm. The methodpreserves top wafer surface roughness of 2 nm, with significant potential for3D integrated systems.Item Embargo Colloidal semiconductor quantum well supraparticles as low-threshold and photostable microlasers(Wiley-VCH Verlag GmbH & Co. KGaA, 2024-08-08) Alves, P. U.; Quinn, G.; Strain, M. J.; Durmuşoğlu, E. G.; Sharma, M.; Demir, Hilmi Volkan; Edwards, P. R.; Martin, R. W.; Dawson, M. D.; Laurand, N.This study introduces and compares the lasing performance of micron-sizedand sphere-shaped supraparticle (SP) lasers fabricated through bottom-upassembly of II-VI semiconductor colloidal quantum wells (CQWs) with theircounterparts made of quantum dots (CQDs). CQWs consist of a 4-monolayersthick CdSe core and an 8-monolayers thick CdxZn1-xS shell with a nominal sizeof 14 × 15 × 4.2 nm, and CQDs of CdSxSe1-x/ZnS with 6 nm diameter. SPs areoptically characterized with a 0.76 ns pulse laser (spot size: 2.88 × 10−7 cm 2 )at 532 nm, and emit in the 620–670 nm spectral range. Results show thatCQW SPs have lasing thresholds twice as low (0.1–0.3 nJ) as CQD SPs(0.3–0.6 nJ), and stress tests using a constant 0.6 nJ optical pump energydemonstrate that CQW SPs withstand lasing emission for longer than CQDSPs. Lasing emission in CQW and CQD SPs under continuous operationyields half-lives of 𝝉CQW SP ≈150 min and 𝝉CQD SP ≈22 min, respectively. Thehalf-life of CQW SPs is further extended to 𝝉QW ≈385 min when opticallypumped at 0.5 nJ. Such results compare favorably to those in the literatureand highlight the performance of CdSe-based CQW SPs for laser applications.Item Open Access Selective cooling and squeezing in a lossy optomechanical closed loop embodying an exceptional surface(Springer, 2024-06-14) Ege, Beyza Sütlüoğlu; Bulutay, CeyhunA closed-loop, lossy optomechanical system consisting of one optical and two degenerate mechanical resonators is computationally investigated. This system constitutes an elementary synthetic plaquette derived from the loop phase of the intercoupling coefficients. In examining a specific quantum attribute, we delve into the control of quadrature variances within the resonator selected through the plaquette phase. An amplitude modulation is additionally applied to the cavity-pumping laser to incorporate mechanical squeezing. Our numerical analysis relies on the integration-free computation of steady-state covariances for cooling and the Floquet technique for squeezing. We provide physical insights into how non-Hermiticity plays a crucial role in enhancing cooling and squeezing in proximity to exceptional points. This enhancement is associated with the behavior of complex eigenvalue loci as a function of the intermechanical coupling rate. Additionally, we demonstrate that the parameter space embodies an exceptional surface, ensuring the robustness of exceptional point singularities under experimental parameter variations. However, the pump laser detuning breaks away from the exceptional surface unless it resides on the red-sideband by an amount sufficiently close to the mechanical resonance frequency. Finally, we show that this disparate parametric character entitles frequency-dependent cooling and squeezing, which is of technological importance.Item Open Access Distraction suppresses high-fat flavor perception(Elsevier Ltd, 2024-04-01) Razzaghi-Asl, Sara; Doğan, Sümeyra Nur; Tekatlı, Muhammet Tahir; Geraldine Veldhuizen, MariaDistraction during eating contributes to overeating, and when habitually eating with distraction, this may contribute to the development of obesity. One of the proposed mediating mechanisms is the suppression of intensity perception in odor and taste. The effect of distraction on fat intensity perception in flavor, the multisensory combination of odor, taste, and other sensory aspects, is still unknown. In this study, 32 participants (22 women) performed a flavor perception task while also performing a distracting working memory task. In each trial, participants were instructed to observe and memorize a string of 3 (low cognitive load) or 7 (high cognitive load) consonants. Then they received a small quantity of a high- or lowfat chocolate drink, and after that, they were asked to select the string they tried to memorize from three answer options. Last, they rated the intensity and fattiness of the flavor. As intended, in the working memory task, we observed that with a high cognitive load (relative to a low cognitive load), accuracy decreased and response times increased. Regarding perception of the flavors, we observed that overall, high-fat drinks were rated as more intense and fattier. Cognitive load and fat content interacted, such that for the low-fat drink, intensity and fattiness ratings were similar under both cognitive loads; however, under the high cognitive load (relative to the low cognitive load), intensity and fattiness ratings for the high-fat drink were lower. Our results show that distraction can impact the perception of fat in high-fat drinks. If distraction primarily reduces perception of high-fat foods, this may pose a particular risk of overeating high-calorie foods.Item Open Access Understanding the suitable alloying conditions for highly efficient Cu- and Mn-doped Zn1-xCdxS/ZnS core-shell quantum dots(Elsevier B.V., 2023-10-20) Kaur, Manpreet; Sharma, Ashma; Erdem, Onur; Kumar, A.; Demir, Hilmi Volkan; Sharma, M.Doping of alloyed colloidal quantum dots (QDs) has garnered significant attention for providing tunable and Stokes-shifted emission. By alloying the host semiconductor nanocrystals (NCs), their band gap can be tuned. With the specific addition of dopant ions, these NCs can emit tunable emissions within the visible spectrum. However, while doped and alloyed quantum dots (QDs) have shown promise for tunable emissions, their emission qualities have not been consistent across the spectrum. Here, we report the synthesis of high-quality Cu- and Mn-doped ZnxCd1-xS (x = 0–1) alloyed QDs by a colloidal non-injection method. In this study, we examined the effect of different dopant ions on the optical properties of similar alloyed nanocrystals. The deposition of a ZnS shell on these doped QDs significantly improves their quantum yield (QY), increasing it from 7.0 % to 50.0 % for Cu-doped QDs and from 30.0 % to 80.0 % for Mn-doped QDs. The Cu-doped QDs exhibit tunable emission from green to red across the visible spectrum by varying the Zn/Cd ratio, whereas the Mn-doped QDs show a fixed orange emission. Interestingly, the Cu-doped alloyed QDs show a contrasting trend in quantum yield (QY) compared to those of Mn-doped QDs when the amount of Cd in ZnCdS alloyed QDs is systematically changed. As the amount of Cd increases in the ZnCdS alloyed QDs, the Cu-doped QDs show both an increase in average lifetime and an increase in QY. In contrast, for the Mn-doped QDs, the decay lifetime values remain fairly constant for different amounts of Cd in the ZnCdS alloyed QDs, but the QY decreases as the amount of Cd increases. The results of this study may facilitate the design of optimal alloying combinations for Cu/Mn-doped QDs in optoelectronic applications. © 2023 The AuthorsItem Open Access Deep-learning-enabled electromagnetic near-field prediction and inverse design of metasurfaces(Optica Publishing Group (formerly OSA), 2023-10-16) Kanmaz, Tevfik Bülent; Öztürk, E.; Demir, Hilmi Volkan; Gündüz-Demir, Ç.Metasurfaces generate desired electromagnetic wavefronts using sub-wavelength structures that are much thinner than conventional optical tools.However, their typical design method is based on trial and error, which is adversely inefficient in terms of the consumed time and computational power. This paper proposes and demonstrates deep-learning-enabled rapid prediction of the full electromagnetic near-field response and inverse prediction of the metasurfaces from desired wavefronts to obtain direct and rapid designs. The proposed encoder-decoder neural network was tested for different metasurface design configurations. This approach overcomes the common issue of predicting only the transmission spectra, a critical limitation of the previous reports of deep-learning-based solutions. Our deep-learning-empowered near-field model can conveniently be used as a rapid simulation tool for metasurface analyses as well as for their direct rapid design. © 2023 Optica Publishing Group.Item Open Access Single-material MoS2 thermoelectric junction enabled by substrate engineering(Nature Research, 2023-05-26) Razeghi, Mohammadali; Spiece, J.; Oğuz, Oğuzhan; Pehlivanoğlu, Doruk; Huang, Y.; Sheraz, Ali; Başçı, U.; Dobson, P. S.; Weaver, J. M. R.; Gehring, P.; Kasırga, Talip SerkanTo realize a thermoelectric power generator, typically, a junction between two materials with different Seebeck coefficients needs to be fabricated. Such differences in Seebeck coefficients can be induced by doping, which renders it difficult when working with two-dimensional (2d) materials. However, doping is not the only way to modulate the Seebeck coefficient of a 2d material. Substrate-altered electron–phonon scattering mechanisms can also be used to this end. Here, we employ the substrate effects to form a thermoelectric junction in ultrathin, few-layer MoS2 films. We investigated the junctions with a combination of scanning photocurrent microscopy and scanning thermal microscopy. This allows us to reveal that thermoelectric junctions form across the substrate-engineered parts. We attribute this to a gating effect induced by interfacial charges in combination with alterations in the electron–phonon scattering mechanisms. This work demonstrates that substrate engineering is a promising strategy for developing future compact thin-film thermoelectric power generators. © 2023, The Author(s).Item Open Access Enhanced generation of higher harmonic from Halide Perovskite Metasurfaces(META Conference, 2023) Tonkaev, P.; Koshelev, K.; Masharin, Mikhail A.; Makarov S.; Kruk S.; Kruk S.Many outstanding properties of halide perovskites provided their applications in optoelectronics. Perovskite films demonstrate outstanding nonlinear properties with large optical nonlinearities comparable to the nonlinear constants of conventional semiconductor materials. Meanwhile, nonlinear properties can be enhanced by the metaphotonic approach. Here we demonstrate a two-order enhancement of fifth-harmonic generation in halide perovskite nonlocal metasurfaces due to high-quality resonance at the generated harmonic wavelength in the visible frequency range. © 2023, META Conference. All rights reserved.Item Open Access Sub-wavelength silicon nano-structuring with direct laser writing(META Conference, 2023) Sabet, Rana Asgari; Tokel, OnurWe present a novel laser nano-lithography method inside the bulk of silicon. We exploit nanosecond laser pulses of 1.55-μm wavelength which are modulated with a spatial light modulator. The created Bessel beams enable direct and highly-controlled subsurface fabrication capability in Si. Using this technique, we demonstrate for the first time, the fabrication of sub-wavelength nano-modifications deep inside Si. We further illustrate nanopatterns of 200-nm width and of sub-micron separation. Such 3D control on sub-wavelength structures inside Si offer exciting possibilities for Si-photonics devices, meta-material and meta-surface in-chip technologies. © 2023, META Conference. All rights reserved.