BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Terahertz detectors based on Si CMOS MOSFETs for characterization of broadband and narrow radiation sources DTSTART;VALUE=DATE-TIME:20220708T091000Z DTEND;VALUE=DATE-TIME:20220708T093000Z DTSTAMP;VALUE=DATE-TIME:20260516T024328Z UID:indico-contribution-91-815@events.ncbj.gov.pl DESCRIPTION:Speakers: Dmytro But (CENTERA Laboratories\, Institute of High Pressure Physics PAS)\nThe so-called "terahertz gap" is gradually being f illed with new compact devices and effective solutions for the detection a nd emission of radiation. In particular\, the development of field-effect -transistors (FET) is starting to play a significant role in this process [1\, 2] and had demonstrated in applications together with pulse free el ectron lasers and gas laser [3\, 4] and fast time-domain system [5]. In t his report\, we present the analysis of different methods which can be app lied for the improvement of detector performance in wide range of frequenc ies. We focus on a standard Si CMOS (complementary metal-oxide-semiconduc tor) process technologies that can be used to produce cost-efficient THz d etectors and sensors which are ready for scaling to sensor lines or arrays . \nWe implement different types of integrated antennas: a patch-type ante nna for the front-side radiation coupling and a slot dipole antenna for th e coupling with a substrate or booster lens. Furthermore\, we extend our r esearch toward the on-chip integrated amplifier. These solutions are not m utually exclusive and can be combined to achieve the best performance.\nAl though the best practical performance is achieved with substrate lens coup led devices\, patch antenna coupling brings the advantage of a strong redu ction in packaging complexity. The disadvantage of patch-antenna coupled d etectors is the relatively small effective area of the antenna which limit s its total efficiency in comparison to a backside-illumination solution w ith the slot antenna. This shortcoming can be improved by an additional di electric lens that is attached to the top of the patch. We simulate and te st the performance of detectors with dielectric lenses of different shapes : a dielectric rod\, hyper-hemisphere\, and aspheric curvature. Several di fferent materials have been employed to fabricate these types of lenses\, like silicon\, sapphire\, or various polymer materials. For example\, the polyethylene hemisphere lens with 4 mm diameter improves the directivity o f the patch antenna by minimum in 1.5 times with an additional advantage o f an improvement in antenna efficiency. \nThe amplifying of the output sig nal – can be realized by using an integrated amplifier implemented on th e same chip. Noise-optimized design and minimized distance between the det ector output and amplifier input results in cost-efficient devices without the deterioration in the signal-to-noise ratio.\nReference: \n[1] Valuši s\, Gintaras\, et al. MDPI Sensors 21.12\, 4092 (2021)\;\n[2] E. Javadi\, et al. MDPI Sensors 21.9 2909 (2021)\;\n[3] Regensburger\, S.\, et al. Opt . expr. 23.16\, 20732-20742 (2015)\;\n[4] But\, D. B.\, et al. J. of App. Phys. 115.16 164514 (2014)\;\n[5] Ikamas\, K.\, et al. Semicond. Sci. Tec hnol.\, 33.12\, 124013 (2018).\n\nhttps://events.ncbj.gov.pl/event/75/cont ributions/815/ LOCATION:Novotel Warszawa Centrum Róża URL:https://events.ncbj.gov.pl/event/75/contributions/815/ END:VEVENT BEGIN:VEVENT SUMMARY:CMOS-based THz detector with on-chip amplifier for imaging applica tions DTSTART;VALUE=DATE-TIME:20220708T093000Z DTEND;VALUE=DATE-TIME:20220708T095000Z DTSTAMP;VALUE=DATE-TIME:20260516T024328Z UID:indico-contribution-91-799@events.ncbj.gov.pl DESCRIPTION:Speakers: Cezary Kołaciński (CENTERA Laboratory\, Institute of High Pressure Physics PAS\, 01-142 Warsaw\, Poland)\nThe non-ionizing n ature of terahertz radiation together with the ability to penetrate throug h common packaging materials have sparked significant interest in THz non- destructive imaging applications. There is a huge need for low-cost and co mpact THz systems\, which will grow with the further discovery of potentia l THz wave applications. A natural solution to this issue is the usage of mainstream semiconductor technologies\, such as complementary metal-oxide- semiconductor (CMOS) lines. The understanding of device properties and the performance of CMOS-based detectors are constantly improving\, resulting in high sensitivity\, low noise\, and broadband devices. \n\nMentioned det ector improvement stimulates the research aimed at the readout circuits ad dressed to these devices. The integration between CMOS-based detector and on-chip readout electronics seems to be a natural solution. This attitude is optimal from the system performance point of view: the path between det ector output and readout input is minimized. This opens up the way for the possibilities in the field of THz systems development and miniaturization . \n\nIn this study\, we concentrate on a lower range of THz frequencies - the vicinity of 300 GHz. Two different types of integrated antennas have been implemented: a patch-type antenna for the front-side radiation coupli ng and a slot dipole antenna for the coupling with the substrate or booste r lens. Furthermore\, we extend our research toward the on-chip integrated amplifier. These solutions are not mutually exclusive and can be combined to achieve the best performance.\nAlthough the best practical performance is achieved with substrate lens coupled devices\, patch antenna coupling brings the advantage of a strong reduction in packaging complexity. The di sadvantage of patch-antenna coupled detectors is the relatively small effe ctive area of the antenna\, which limits its total efficiency compared to a backside-illumination solution with the slot antenna. This shortcoming c an be improved by an additional dielectric lens attached to the top of the patch. \n\nThe output signal amplifies can be realized by using an integr ated amplifier implemented on the same chip. Noise-optimized design and mi nimized distance between the detector output and amplifier input results i n cost-efficient devices without the deterioration in the SNR (signal-to-n oise ratio). This work uses an integrated circuit based on a differential pair loaded by two resistors to achieve a voltage gain of 20V/V (26dB).\n\ nDescribed above solutions enable to increase of the output signal (and th e practical SNR) by a total factor of approx. ~160 (at 275 GHz of radiatio n frequency for patch antenna detector)\, where the factor x8 is related t o the increased effective area as well as improved efficiency of the anten na and the factor of x20 - due to the amplifier circuit.\n\nhttps://event s.ncbj.gov.pl/event/75/contributions/799/ LOCATION:Novotel Warszawa Centrum Róża URL:https://events.ncbj.gov.pl/event/75/contributions/799/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigation of electromagnetic coupling between the antenna and split-ring-based metasurface in CMOS technology DTSTART;VALUE=DATE-TIME:20220708T085000Z DTEND;VALUE=DATE-TIME:20220708T091000Z DTSTAMP;VALUE=DATE-TIME:20260516T024328Z UID:indico-contribution-91-800@events.ncbj.gov.pl DESCRIPTION:Speakers: Alexander Chernyadiev (CENTERA\, Institute of High P ressure Physics PAS)\nPhysics of coupling of resonating structures has bee n investigated for many decades\, yet still new effects are discovered due to the better understanding of the underlying processes and due to the sh ift of the focus from the classical resonators to the quantum objects\, to meta-atoms and to the nanoscale in general. The well-known effect in atom ic physics of the electromagnetically induced transparency was recently de monstrated with optical metamaterials stacked together. It became feasible to realize a near-field sensor based on coupled resonators for detection and spectral analysis of different 2-D materials\, chemical compounds\, or biological materials and structures thanks to the dramatic increase of co upled resonators' sensitivity to the changes of the electromagnetic proper ties of the surrounding medium. Furthermore\, this concept can be efficien tly implemented using the technology platform which is offered by the well -developed mainstream silicon (Si) complementary metal-oxide-semiconductor technology (CMOS). It is commercially available\, reliable\, and due to t he extended metal stack’s functionalities\, providing many possibilities for designing high-frequency components. For example\, 90-nm Si CMOS tech nology served as a platform for designing a terahertz (THz) sensor of huma n body-emitted radiation in a broad range of frequencies 0.1-1.5 THz. In t his paper we report on the investigations of electrodynamic properties of a metasurface-coupled THz antenna with the fundamental resonance frequency of 350 GHz which is implemented in a 180-nm CMOS technology.\nThe structu re under investigation is essentially a THz detector based on a pair of n- type CMOS transistors. The detector is equipped with a differential slot a ntenna with an outer diameter of 450 µm. A single split-ring resonator ha s a size of 65×30 µm with a gap of 10 µm. The numerical simulation of t he electromagnetic properties of coupled resonators was performed by the F inite Element Method in CST Studio Suite. The experimental measurements we re performed with the use of the frequency-domain terahertz platform with the CW THz source based on a photomixer of the TOPTICA's Terascan platform . When both antenna and a split-ring are placed together and their resona nce is tuned to the same frequency\, the electro-magnetic coupling between them results in strong shifting of peak frequencies. One peak shifts towa rds the lower frequencies\, another towards the higher ones. 42% splitting from the initial resonance frequency was recorded. When the antenna is co upled to three split-rings the peaks shift even further from each other. I f the antenna is coupled to a whole system\, a metasurface of split-rings\ , then the 58% splitting from the resonance frequency was recorded. \nSumm arizing this report\, we show that the efficient electromagnetic coupling between the slot antenna and the metasurface of split-ring resonators can be realized in a commercially available 180-nm CMOS technology.\n\nhttps:/ /events.ncbj.gov.pl/event/75/contributions/800/ LOCATION:Novotel Warszawa Centrum Róża URL:https://events.ncbj.gov.pl/event/75/contributions/800/ END:VEVENT BEGIN:VEVENT SUMMARY:Multichannel transmission for the future wireless THz telecommunic ation links DTSTART;VALUE=DATE-TIME:20220708T095000Z DTEND;VALUE=DATE-TIME:20220708T101000Z DTSTAMP;VALUE=DATE-TIME:20260516T024328Z UID:indico-contribution-91-717@events.ncbj.gov.pl DESCRIPTION:Speakers: Paweł Komorowski (Institute of Optoelectronics\, Mi litary University of Technology)\nTerahertz (THz) radiation brings the att ention of researchers and entrepreneurs for at least a few decades and has already found numerous applications in various areas\, such as medical di agnostics\, nondestructive testing\, detection of dangerous materials and objects\, security or telecommunication. This work focuses on the latter a rea of potential applications and aims at the development of the multiplex ing methods for the future THz data transmission links. We propose the uti lization of the properly designed THz diffractive optical elements (THz-DO Es) for manipulation of the THz waves on both sides of the data transmissi on link to\, respectively\, multiplex and demultiplex signals.\nDOEs intro duce defined attenuation and phase retardation distributions to the illumi nating optical field. Clever adjustment of these parameters allows to resh ape incoming radiation into almost arbitrarily chosen patterns. Moreover\, the size of the crucial elements of such structures depends linearly on t he wavelength\, which in case of THz and sub-THz bands is in order of sing le millimeters or its fractions. Therefore\, in many cases\, THz-DOEs can be manufactured using relatively simple and cheap techniques\, such as ext rusion-based 3D printing.\n In this work\, we present methods of separatio n of THz beams propagating in the single optical channel\, also with the f requency division. We have designed\, optimized and manufactured THz-DOEs redirecting the incoming radiation into several focal spots. Two approache s have been investigated – single-frequency and multi-frequency operatio n. In the first case\, a monochromatic THz beam is divided into three sepa rate focal spots\, while in the second one a polychromatic beam is redirec ted at an angle dependent on the frequency. All structures have been succe ssfully verified experimentally and the obtained results comply with the t heoretical simulations. Moreover\, a setup demonstrating simultaneous dual -channel transmission at 300 GHz and 330 GHz has been demonstrated.\n\nhtt ps://events.ncbj.gov.pl/event/75/contributions/717/ LOCATION:Novotel Warszawa Centrum Róża URL:https://events.ncbj.gov.pl/event/75/contributions/717/ END:VEVENT END:VCALENDAR