ultra stable terahertz frequency synthesizers and extremely sensitive heb d etectors up to 70 thz n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB D etectors up to 70 THz. PowerPoint Presentation
Download Presentation
Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB D etectors up to 70 THz.

Loading in 2 Seconds...

play fullscreen
1 / 45

Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB D etectors up to 70 THz. - PowerPoint PPT Presentation


  • 431 Views
  • Uploaded on

Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB D etectors up to 70 THz. Mikhail L. Gershteyn President, Insight Product Co. www.insight-product.com Phone: (617) 965-8151 E-mail: InsightProduct@yahoo.com. Overview.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB D etectors up to 70 THz.' - Audrey


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
ultra stable terahertz frequency synthesizers and extremely sensitive heb d etectors up to 70 thz

Ultra Stable Terahertz Frequency Synthesizers and Extremely Sensitive HEB Detectors up to 70 THz.

Mikhail L. Gershteyn

President, Insight Product Co.

www.insight-product.com

Phone: (617) 965-8151

E-mail: InsightProduct@yahoo.com

overview
Overview
  • 1. Advancing frequency stabilization techniques to Terahertz range.
  • 1.1 Applications of frequency stabilized sources.
  • 1.1.1 Narrow band phenomena’s in Nature.
  • 1.1.2 Narrow band systems technologies.
  • 1.2 Stabilized sources in MMW and THz.
  • 1.2.1 Comparison of Stabilized Sources.
  • 1.2.2 THz synthesizers from Insight Product Co.
  • 2. Superconducting Hot Electron Bolometer (HEB) Mixers & Detectors
  • 2.1 Applications of HEB Mixers & Detectors
  • 2.2 Direct Detectors and Mixers
  • 2.3 Comparison of Detectors & Mixers in THz area.
  • 2.4 Superconducting Hot Electron Bolometer (HEB) detectors and mixers from Insight Product
  • 3. Conclusions
  • 4. Acknowledgments
applications of synthesized sources
Applications of Synthesized Sources
  • Gas Spectroscopy
  • Security: Gas detection systems
  • Accessing water content in tissue
  • Medical imaging: cancer tissue identification
  • Heterodyne Receiving Systems
  • Astrophysics
  • Material characterization and testing
  • NMR/ MRI, EPR, quantum computers
  • Plasma diagnostics, Gyrotron cold testing
  • Communications: high bandwidth channels
naturally occurring physical narrow band phenomena
Naturallyoccurring physical narrow-band phenomena
  • Absorption and emission spectrum of various molecules
  • It is well know that each molecule has a distinctive frequency fingerprint of emitting and absorbing electromagnetic waves. There are very sharply, narrow-band frequency effects observed, called “absorption lines”.
  • Security Application: The THz absorption spectrum of various gases yields distinct regions of absorption which could be used to differentiate hazardous gases from benign ones.
  • Applications: Air Monitoring
  • Atmospheric Monitoring via satellite.
  • Monitoring of emissions from Industrial Chemical Processing.
  • Real-time monitoring of chemical processes in gas phase.
  • Scientific Application: Gas Spectroscopy
naturally occurring physical narrow band phenomena ii
Naturallyoccurring physical narrow-band phenomena II
  • Resonance of mediums with minuscule absorption
  • Mechanical resonance: quartz. Quartz vibrates because it basically does not absorb acoustic wave.
  • Professor H. Frohlich’s concept: cell membranes participate in synchronized coherent high-frequency oscillations (10s of GHz up to 100s of GHz) : therefore dynamic biological functionality can be influenced by weak EM radiation at certain narrow-band frequency.
  • Biological Coherence & Response to External Stimuli (Springer, 1988) edited by H. Frohlich
  • First experimental demonstration of the effect of weak specific mm-wave frequencies on living organisms was obtained in the early 1970s by Academician N. N. Devatkov et al. group in USSR.
  • One of the latest reviews on the subject, entitled “Non-thermal Biological Effects of Microwaves” (Microwave Review, November 2005) was published by Dr. Igor Y. Belyaev (Department of Genetics, Microbiology and Toxicology, Stockholm University, Sweden)
  • http://www.mwr.medianis.net/pdf/Vol11No2-03-IBelyaev.pdf
  • Biomedical Applications: Millimeter Wave Therapy
naturally occurring physical narrow band phenomena iii
Naturallyoccurring physical narrow-band phenomena III
  • EPR (Electron Paramagnetic Resonance) and NMR/DNP (Nuclear Magnetic Resonance/ Dynamic Nuclear Polarization)
  • NMR enhancement by EPR
  • Applications:
  • Material characterization
  • Medical Imaging
  • Biological & Chemical Research.
naturally occurring physical narrow band phenomena iv
Naturallyoccurring physical narrow-band phenomena IV

Frequency shift effects.

    • Doppler effect: frequency change of EM coming from a moving source depending on the velocity of motion. Also the reflection of EM against a moving target causing a frequency shift in reflected signal.
    • Frequency shift is proportional to velocity over speed of light.
  • ∆f/f= v/c
  • General Applications: Motion detectors and velocity estimators.
  • Security Applications: Intruder detection by motion.
narrow band systems in technology
Narrow bandSystems in Technology
  • Systems in Technology and Science use narrow-band signals in order to achieve:
  • high selectivity
  • high frequency resolution
  • high sensitivity
  • high stability
  • phase detection
narrow band systems in technology ii
Narrow bandSystems in Technology II
  • Communications – we use synthesized sources to differentiate one channel from another and to inhibit interference. Also the narrow-frequency band allows the utilization of heterodyne receiving systems which offer exceptional sensitivity. This also enables broad receiving range with limited transmitted power.
narrow band systems in technology iii
Narrow bandSystems in Technology III
  • Radars - Time for reflected signal to reach the sensor is used to calculate distance. Narrow band pulses are used to increase sensitivity, at the receiver end, and in Doppler shift radars to measure velocity. In FM (frequency modulation) radars the distance to the target if inferred from the change in frequency between reflected signal and current signal. In this case the frequency must be very accurately defined for every time point, so a narrow-banded time dependent signal is necessary.
narrow band systems in technology iv
Narrow bandSystems in Technology IV
  • Selective receivers in Astrophysics and Atmosphere Investigations
  • We need to receive a signal in a certain frequency range corresponding to emission of various molecules in space. Heterodyne receivers are used, since they yield excellent sensitivity. The heterodyne LO (local oscillator) needs to have high frequency stability.
narrow band systems in technology v
Narrow bandSystems in Technology V
  • Imaging system for medical and security applications.
  • In imaging systems, narrow-band signals together with heterodyne receiving technique increase the sensitivity of reception of the signal, expedite the frame rate, and boast resolution.
  • An example in THz area, I’d like to refer to the latest results of Peter Siegel et al. (JPL)
heterodyne active imager
Heterodyne Active Imager

Courtesy of Dr. Peter H. Siegel, JPL

heterodyne active imager1
Heterodyne Active Imager

Courtesy of Dr. Peter H. Siegel, JPL

narrow band systems in technology vi
Narrow bandSystems in Technology VI
  • Systems for material characterization and plasma diagnostics :
  • Narrow-band signal allows:
  • a ) increased sensitivity
  • b) selectivity by frequency
  • c) phase measurements (especially relevant in plasma diagnostics)
  • d) increased temporal resolution (faster measurements)
  • e) introduce monitoring capability
narrow band systems in technology vii
Narrow bandSystems in Technology VII
  • Gas absorption spectrometers and gas detectors.
  • The natural absorption phenomena are narrow-banded.
  • The typical “absorption line” width of any gas at a pressure of 1 Torr and standard temperature is 10-6 (∆f/f) in the terahertz range.
  • Therefore to match the “absorption line” we need to have a probing signal which has at least 10-6 (∆f/f) frequency stability (both long and short term stability).
  • Security Application: Local atmosphere monitoring for specific known substances, biological agents, or gases.
  • Monitoring of chemical reactions.
  • Monitoring of technological processes.
sources of frequency stable signal in thz range
Sources of frequency stable signal in THz range
  • Synthesized frequency stable sources in microwaves (up to 20 GHz) are well developed and widely available. One of the latest reviews was written by Jack Browne.

Reference:

“Frequency Synthesizers Generate Clean Signals:

Frequency synthesizers come in many shapes and sizes, although

the ultimate goal in any design is to generate stable output

frequencies with minimal spurious and phase noise.”

Jack Browne Microwaves & RF [Systems & Subsystems]

ED Online ID #10016March 2005

(http://www.mwrf.com/Articles/Index.cfm?ArticleID=10016&pg=2)

sources of frequency stable signal in thz range ii
Sources of frequency stable signal in THz range II
  • Lasers (C02 pumped)
  • Pros: High output power (~10-100 mW) & high frequency stability (better than 300 KHz line).
  • Cons: Fixed frequency, lacks tunability, limited possibility for frequency and phase modulation and manipulation, large bulky devices, available on only several specific frequencies.
sources of frequency stable signal in thz range iii
Sources of frequency stable signal in THz range III
  • Stabilized Quantum Cascade Lasers (QCL)
  • Pros: High output power (1-50 mW),

good stability (less than 300 kHz)

  • Cons: Small tuning bandwidth (~10 GHz),

Not available on all frequencies.

sources of frequency stable signal in thz range iv
Sources of frequency stable signal in THz range IV
  • Photo-mixers
  • Pros: wide tunable bandwidth (several hundred GHz)
  • Cons: low output power (1 microWatt at 1 THz, 0.1 microWatt at 3 THz), large bulky devices.
sources of frequency stable signal in thz range iii1
Sources of frequency stable signal in THz range III
  • Direct Multiplier chains
  • These devices use multipliers and amplifiers to go from microwave stable source (up to 20 GHz) to THz range.
  • Pros: Solid-state, high frequency stability when input signal is from a frequency synthesizer, compact, commercially available, wide tunability (~15%).
  • Cons: Complex design. Amplifier and multi-cascaded chains (FEMs) are required to reach THz frequencies.
  • Output power drops exponentially with increasing frequency.
  • Low output power (1-2 microWatt at 1.25 THz)
  • Do not go higher than 1.7 THz.
  • Low efficiency (less than 0.5%)
  • Multiple component spectrum of output signal with different harmonics.
  • Possibility for frequency and phase modulation and manipulation is limited by what’s available in the driving microwave source.
sources of frequency stable signal in thz range iv1
Sources of frequency stable signal in THz range IV
  • PLL (Phase-lock loop) Systems based on BWO (Backward Wave Oscillator, a.k.a. “carcinotron” or “backward wave tube”)
  • BWO by PLL locked to harmonic of microwave stable source.
  • Pros: Wide tunability band (~20 %)
  • Relatively high output power (2-8 milli-Watt at 1 THz)
  • Possibility of quick frequency and phase modulation and manipulation.
  • Simple (“one line”) output spectrum.
  • Cons:
  • Need high voltage power supply and magnet
  • Do not go above 1.5 THz
sources of frequency stable signal in thz range v
Sources of frequency stable signal in THz range V
  • Hybrid systems – PLL locked Sources plus Multipliers (in development)
  • PLL locked BWO sources (200-300 GHz) are multiplied to THz region.
  • Pros: Wide tunability band.
  • Possibility of quick frequency and phase modulation and manipulation.
  • Projected cover from 1 up to 3 THz with power of about 10 microWatt.
  • Cons: Need high voltage power splay and magnet.
insight product synthesizers insight fs 36 ghz 1 25 thz
Insight Product Synthesizers (Insight FS) 36 GHz – 1.25 THz
  • Typical Output Power (in milliWatt) and Tuning Frequency Range.
  • 370 - 535 GHz: 4-15 mW
  • 526 - 714 GHz: 4-15 mW
  • 667 - 857 GHz: 4-15 mW
  • 789 - 968 GHz: 3-8 mW
  • 882 - 1,111 GHz: 2-8 mW
  • 1,034 – 1,250 GHz: 0.5-2 mW
insight fs synthesizers ii
Insight FS Synthesizers II

Advantages:

  • Extremely high frequency stability (up to 10-11 =∆f/f).
  • High output power (several mW at 1 THz).
  • Each synthesizer covers a full waveguide band.
  • Each synthesizer operates independently in free running mode as generator or with microwave signal generator as synthesizer.
  • Insight FS provides several options for frequency and amplitude modulation (analog FM/AM modulation, frequency manipulation, pulses modulation). 
  • Insight FS are compact in size and controlled by IEEE, analog input, or manually.
insight fs synthesizers iii
Insight FS Synthesizers III

“For millimeter-wave frequencies, Insight Product Co. (www.insight-product.com) offers

a line of frequency synthesizers in full waveguide bands from 120 to 180 GHz,

with output-power levels of 30 mW or more. Ideal for measurement and astronomy applications,

these synthesizers can be equipped with optional AM and FM capabilities and GPIB remote control.”

March 2005, Microwaves & RF Journal

schematics of direct vs heterodyne detection
Schematics of direct vs. heterodyne detection

Courtesy of Drs. Peter H. Siegel and Robert J. Dengler, CALTECH & JPL

650 GHz: typical bolometer NEP @ 300 degrees K = 10-11 W/Hz2

650 GHz: typical mixer NEP @ 300 degrees K = 10-15 - 10-14 W/Hz2

superconducting hot electron bolometer heb mixers
Superconducting Hot Electron Bolometer (HEB) Mixers
  • Applications:
  • Terahertz Spectroscopy
  • Terahertz RadioAstronomy
  • Remote sensing of Earth Atmosphere
  • Active Terahertz Imaging
  • Security Imaging and Monitoring
superconducting hot electron bolometer heb mixers ii
Superconducting Hot Electron Bolometer (HEB) Mixers II
  • Currently the following large-scale projects may benefit from HEB mixers:
  • Large-scale government projects such as SOFIA, FIRST, & ALMA.
  • Astronomy projects: SMILES, EOS-MLS.
  • Planetary science projects: ROSETTA, Mars explorer.
superconducting hot electron bolometer heb mixers iii
Superconducting Hot Electron Bolometer (HEB) Mixers III
  • “Superconducting hot electron bolometer (HEB) mixers are the choice of device for the frequencies between 1.5 and 6 THz. They are complementary to SIS mixers which work as quantum noise limited detectors up to about 1 THz. An HEB consists of a niobium-nitride (NbN) superconducting bridge with nanometer or submicron dimensions, contacted by thick gold pads. THz radiation signals are coupled into the bridge through a lens and an on-chip antenna (quasi optical). The heterodyne mixing process makes use of the resistive transition between the superconducting state and the normal state of the superconducting bridge, induced by the heating of THz radiation signals. Click for a schematic of the detector principle. To reach a high intermediate frequency (IF) bandwidth, an extremely thin NbN film with a high critical temperature is used, optimized for phonon cooling.”

–SRON (Netherlands Institute for Space Research)

hot electron bolometer heb mixers iv
Hot Electron Bolometer (HEB) Mixers IV
  • HEB Mixers, Advantages
  • Above about 1 THz Hot Electron Bolometer mixers offer the best sensitivity and lowest noise of all the technology for the coherent detection of radiation.
  • Wide converstion gain bandwidth and noise bandwidth ( both up to 4.5 GHz).
  • Low Heterodyne source power (about 1 microW).
superconducting hot electron bolometer heb detectors
Superconducting Hot Electron Bolometer (HEB) Detectors
  • Applications of Superconducting HEB Detectors:
  • Fast and/or wide range pulses of terahertz radiation for biological investigations, and real-time monitoring.
  • Passive Imaging
  • Active Imaging with short pulses
heb receiver in chile
HEB receiver in Chile

Courtesy of Dr. Gregory Goltsman

comparison of mixers
Comparison of Mixers

Courtesy of Dr. Gregory Goltsman

s heb mixer system at 7 9 thz w components and lhe cryostat
S. HEB mixer System at .7-.9 THZ w/ components and LHe cryostat
  • Quasioptical NbN mixers
  • Hyper-hemispherical Si lens
  • Mixer holder with SMA connector
  • Bias-T adapter
  • Cryogenically cooled HEMT amplifiers (four options)
  • Liquid helium cryostats (3 options)
  • Cryogenically cooled IR filter
  • Teflon input cryostat window
  • Room-temperature (RT) amplifiers (3 options)
  • HEMT amplifier power supply
  • RT amplifier power supply
  • Mixer power supply
s heb mixers specs
S. HEB mixers specs
  • 1 THz: ~800 ° K = Noise Temperature
  • 2 THz: ~1,000 ° K = Noise Temperature
  • 4 THz: ~1,200 ° K = Noise Temperature
  • LO Power required < 1µW
  • Bandwidth ~ 4.5 GHz
s heb detectors specs
S. HEB Detectors specs
  • 0.3 – 3.0 THz Detectors:
  • NEP= 3-5*10-13 W*Hz-0.5; Response time= 50 ps
  • NEP= 5-7*10-14 W*Hz-0.5; Response time=1 ns
s heb detectors specs ii
S. HEB Detectors specs II
  • 0.1 – 30 THz Detectors:
  • NEP= 1-2*10-10 W*Hz-0.5; Response time= 50 ps
  • NEP= 6-8*10-11 W*Hz-0.5; Response time=1 ns
s heb detectors specs iii
S. HEB Detectors specs III
  • 25 – 70 THz Detectors:
  • NEP= 4-5*10-12 W*Hz-0.5; Response time= 50 ps
  • NEP= 1-2*10-12 W*Hz-0.5; Response time=1 ns
conclusions
Conclusions
  • THz band synthesized sources and ultra sensitive detectors are well developed are commercially available.
  • Most of the applications thus far lie in scientific research and government R&D.
  • Technology is ready designing more widely used commercial applications, for security, medical imaging, air pollution monitoring, and biomedical therapy, and real-time monitoring of chemical and industrial processes.
acknowledgments
Acknowledgments
  • Special thanks to the following individuals:
  • Dr. Peter H. Siegel for discussions, and materials.
  • Dr. Gregory Goltsman for discussions, and materials.
  • Dr. Lev I. Gershteyn for discussions.
  • Arkady Gershteyn for discussions, and help with presentation of content.
  • Matt Thomas, for organizing SURA conference.

© Insight Product Co. 2006