Aerospace and Defense
Riza’s Defense Optics activities started from his Caltech Ph.D. student days in the mid-80’s where he showed for the first time how Acousto-Optics could be used to control transmit and receive mode RF phased array radars/antennas (Applied Optics 1991) including simultaneous multiple beamforming implementing RF spatial beam multiplexing (IEEE PTL 1992). Later work by Riza at General Electric revolved around developing next generation highest phase stability acousto-optic (AO) RF signal processors such as convolvers, correlators, and spectrum analyzers for wide instantaneous bandwidth Electronic Warfare (EW) applications (Applied Optics 1992, 1994; IEEE PTL 1995). Additional AO signal processing innovations included powerful Range-Doppler (SPIE 1998) and Nulling filter (SPIE 1994, 1996) optical implementations suited for extreme RF bandwidth and signal complexity radar signal processing. These Riza invention later underwent prototyping and testbed tech transfers at US Air Force Rome Labs and Photonics Systems, Inc., Melbourne, Florida. In 1992, Riza also invented a 2-D Spatial Light Modulator (SLM)-based powerful high tap and weight count time-delay-based transversal Radio Frequency (RF) filter (US Patent 5329118). Later the Riza lab designed and demonstrated a variety of such time delay-SLM based extreme programmability RF filters using fiber-optics, optical digital MEMS, Liquid Crystal SLM, and AO devices, including demonstrations of RF notch filters with suppression ranges of the RF notch signal power between 50 dB and 80 dB. For example, in 2004, Riza introduced a compact polarization independent version of his original SLM-based RF filter using a Digital Micromirror Device (Applied Optics). In 1995 for tech transfer & commercialization, Lockheed Martin acquired Riza’s GE patents on radar controls. In 1999, Riza wrote the Chapter on AO signal processing for RF signals in the Wiley Encyclopedia of Electrical & Electronics Engineering.
Another aspect of the Riza group innovations while at GE and later in academia includes a series of pioneering photonic beamforming control systems for Phased Array Radars and Antennas for both narrowband and wideband operations. These innovations formed the most diverse designs for RF beamformer proposed as they engaged a diverse tool set of device technologies including phase control liquid crystals (LCs), polarization rotation LCs, polarization sensitive LC gratings, optical MEMS, AOs, liquid lens, fibers, fiber gratings, wavelength tunable and broadband sources, wavelength tunable filters including multi-wavelength selection, wavelength division multiplexers and solid-optics (in IEEE, OSA, SPIE, Elsevier Publications & US Patents). These works also included the first high speed designs and improvements to realize multiple simultaneous phased array antenna beams in space (IEEE 1992, SPIE &1EEE 2003). In 1997, Riza edited the most comprehensive book in the field of Photonics for Antenna/Radar Controls (SPIE Press). In 2001, Riza invented the most flexible photonic beamformer interface for phased array antennas using LC on silicon SLM device (IEEE 2001, Elsevier 2003). In 2004, Riza invented new Hybrid Photonic Signal Processing technique that for the first time combines the worlds of analog and digital photonic signal processing leading to world record numbers of 16 bits RF time delay controls with both long time delays and at high time resolutions (IEEE JLT). In 2009, Riza proposed the first silicon photonics wideband RF phased array antenna beamformer design (SPIE 2010) and a decade later, this subject continues to be a hot topic of research.
In 2002, Riza also pioneered a novel hybrid optical-RF phased array antenna control system that used the same optical hardware to both control an RF array antenna and a steered freespace optical beam (US SBIR 2002). Riza is also a pioneer in the use of optics for security systems as in 1994 (IEEE 1995, SPIE 1996), he pioneered the first optical security systems using multi-dimensional optical ID cards including use of interferometric sensing and RF coded card ID generation.
Phased Array Radar/Antenna Controls
Journal Publications:
- N. A. Riza and D. Psaltis, “Acousto-optic signal processors for transmission and reception of phased array antenna signals,” Applied Optics, Vol.30, No.23, pp.3294-3303, 1991.
- N. A. Riza, “A transmit/receive time delay optical beamforming architecture for phased array antennas,”Applied Optics ,Vol.30, No. 32, pp.4594-4596, Nov., 1991.
- N. A. Riza, “An acousto-optic phased array antenna beamformer with independent phase and carrier control using single sideband signals,”IEEE Photonics Tech. Lett., Vol.4, No.2, pp.177-179, February, 1992.
- N. A. Riza, “Acousto-optic architecture for two dimensional beam scanning in phased array antennas,”Applied Optics , Vol.31, No.17, pp.3278- 3284, June 10, 1992.
- N. A. Riza, “An acousto-optic phased array antenna beamformer for multiple simultaneous beam generation,”IEEE Photonics Tech. Lett., Vol.4, No.7, pp.807-809, July, 1992.
- N. A. Riza, “A compact high performance optical control system for phased array radars,”IEEE Photonics Tech. Lett., Vol.4, No.9, pp.1073-1076, Sept., 1992.
- N. A. Riza, “Liquid crystal-based optical control of phased array antennas,”IEEE /OSA Journal of Lightwave Technology, Vol.10, No.12, pp. 1974-1984, Dec., 1992.
- N. A. Riza, “Experimental demonstration of an acoustooptic system for two dimensional phased array antenna scanning,”Applied Optics , Vol. 32, No. 11, pp. 1936-1942, April 10, 1993.
- N. A. Riza, “Acousto-optic liquid crystal analog beamfomer for phased array antennas,” Applied Optics ,Vol. 33, No.17, pp. 3712-3724, June 10, 1994.
- N. A. Riza, “Liquid crystal-based optical time delay units for phased array antennas,” IEEE /OSA Journal of Lightwave Tech , Vol.12, No.8, August, 1994.
- N. A. Riza and N. Madamopoulos, “High Signal-to-Noise Ratio Birefringence Compensated Optical Delay Line using a Noise Reduction Scheme,” Optics Letters ,Vol.20, No.22, pp.2351-2353, Nov.15, 1995.
- N. A. Riza and N. Madamopoulos, “Phased Array Antenna Maximum Compression Reversible Photonic Beamformer using Ternary Designs and Multiple Wavelengths,” Applied Optics, Vol.36, No.5, pp.983-996, Feb.10, 1997.
- N. A. Riza and N. Madamopoulos, “Microwave band demonstration of a reflective geometry fiber and free-space binary photonic delay line,”IEEE Microwave & Guided Wave Lett., Vol.7, No.4, pp. April 1997.
- N. A. Riza and N. Madamopoulos, “ Characterization of a ferroelectric liquid crystal based time delay unit for phased array antenna applications,” IEEE /OSA Journal of Lightwave Tech , Vol.15, No.7, pp.1088-1094, July, 1997.
- N. A. Riza, “Analog Vector Modulation-Based Widely Tunable Frequency Photonic Beamformer for Phased Array Antennas,” Joint Special Issue of IEEE /OSA Journal of Lightwave Tech and IEEE Microwave Theoy & Techniques Journal, Vol.45, No.8, pp.1508-1512, Aug., 1997.
- N. Madamopoulos and N. A. Riza, “Directly modulated semiconductor laser fed photonic delay line with ferroelectric liquid crystals,” Applied Optics, Vol.37, No.8, pp.1407-1416, March 10, 1998.
- N. Madamopoulos and N. A. Riza, “ Adaptable delay balanced loss binary photonic delay line architectures using polarization switching,” Optics Communications , Vol.152, pp.135-143, June 15, 1998.
- N. A. Riza and N. Madamopoulos, “Photonic delay line using electrically switched gratings in polymer dispersed liquid crystals,” Optical Engineering, Vol.37, No.11, pp.3061-3065, Nov. 1998.
- N. Madamopoulos and N. A. Riza, “Polarization Sensitive Hologram-based Photonic delay lines,” Optics Communications, Vol. 157, pp.225-237, 1 Dec., 1998.
- N. A. Riza and N. Madamopoulos, “ Synchronous amplitude and time control for an optimum dynamic range variable photonic delay line,” Applied Optics , Vol.38, No.11, pp.2309-2318, 10 April 1999.
- N. A. Riza, “ Sensor Controls See the Light,” IEEE Circuits and Devices Magazine, pp.14-21, May 1999.
- N. Madamopoulos and N. A. Riza, “All-fiber connectorized compact fiber optic delay-line modules using three-dimensional polarization optics,” Optical Engineering, Vol. 39, No. 9, pp. 2338-2344, September 2000.
- N. A. Riza, “Comment: on Wavelength controlled photonic true time delay for wideband applications,” IEEE Photon. Tech. Lett., Vol. 17, No.12, Dec. 2005.
- N. A. Riza and S. Sumriddetchkajorn, “Micromechanics-based wavelength-sensitive photonic beam control architectures and applications,” Applied Optics, Vol. 39, No. 6, pp. 919-932,20 Feb. 2000.
- M. J. Mughal and N. A. Riza, “Compact acousto-optic high speed variable attenuator for high power applications,” IEEE Photonics Technology Letters, 14(4), 510-512, April (2002)
- N. A. Riza, M. A. Arain, and S. A. Khan, “Analog-Digital Variable Fiber-Optic Delay Line,” IEEE/OSA Journal of Lightwave Technology, vol.22, No.2, pp.619-624, Feb. 2004.
- N. A. Riza, “Comment: on Wavelength controlled photonic true time delay for wideband applications,” IEEE Photon. Tech. Lett., Vol. 17, No.12, Dec. 2005.
- N. A. Riza, “High-Speed High-Isolation 22 Fiber-Optic Switch for Wideband Radar Photonic Beamforming Controls,” IEEE/OSA Journal of Lightwave Technology, Special Issue on Microwave Photonics, Aug.15, 2008.
- N. A. Riza, “Switchless Hybrid Analog-Digital Variable Optical Delay Line for RF Signal Processing,” SPIE Optical Engineering Journal, OE Letters, March 2009.
- S. Fathpour and N. A. Riza, “Silicon Photonics-Based Wideband Radar Beamforming – A Basic Design,” SPIE Optical Engineering Journal, Vol.49 (1), Jan. 2010.
- N. A. Riza, S. A. Reza and P. J. Marraccini, “ Electronically Controlled Agile Lens-Based Broadband Variable Photonic Delay Line For Photonic and RF Signal Processing.” Applied Optics, Vol.45, No.35, pp.6718-6725, Dec.10, 2010.
Conference Publications:
- N. A. Riza, “Acousto-optic architectures for multi-dimensional phased array antenna processing,” in Opt. Technol. Microwave Appl. Conference Proceedings of the SPIE, Vol. 1476, pp.144-156, 1991.
- N. A. Riza, “Acousto-optic techniques for phased array antenna processing,” in Emerging Optoelec. Tech. Conference Proceedings of the SPIE, Vol. 1622, pp.164-167, Dec., 1991.
- N. A. Riza, “High speed two dimensional phased array antenna scanning using acousto-optics,”Opto. Electronic Signal Processing for Phased Array Antennas III Conference Proceedings of the SPIE, Vol. 1703, pp. 460-468, 1992.
- N. A. Riza, “Liquid crystal-based optical time delay control system for wideband phased arrays,” Analog Photonics OE/Fibers Conference Proceedings of the SPIE, Vol. 1790, pp.171-183, 1992.
- N. A. Riza, “Phased array antenna control using liquid crystals,” Analog Photonics OE/Fibers Conference Proceedings of the SPIE, Vol. 1790, pp.65-75, 1992.
- N. A. Riza, “A compact phased array antenna controller for air traffic radars,” IEEE LEOS Annual Meeting Proceedings, EOS3.4, pp.386-387, Nov., 1992.
- N. A. Riza, “Multiple-simultaneous phased array antenna beam generation using an acousto-optic system,” Analog Photonics OE/Fibers Conference Proceedings of the SPIE, Vol. 1790, pp.95-102, 1992.
- N. A. Riza and J. Johnson, “Electro-optic controllers for phased array radars,” in the PSAA-III, The DARPA Symposium on Photonic Systems for Antenna Applications, Jan.20-22, 1993,Naval Postgraduate School, Monterey, California.
- N.A. Riza, “A compact electrooptic controller for microwave phased array antennas,” SPIE Annual Meeting Conference Proceeding on Optical Implementation of Information Processing, Vol. 2026, pp. 286-296, July, 1993.
- N.A. Riza, “Three dimensional optical time delay units for radar,” SPIE Annual Meeting Conference Proceeding on Optical Implementation of Information Processing, Vol. 2026 pp. 227-237, July, 1993.
- N.A. Riza, “An optical control system for millimeter wave phased array antennas,”SPIE Annual Meeting Conference Proceeding on Optical Implementation of Information Processing, Vol. 2026, 344-351, July, 1993.
- N. A. Riza, J. Johnson, and J. Prince, “SLM-based optical time and phase delay control for phased array radars,” PSAA-IV, The DARPA Symposium on Photonic Systems for Antenna Applications, Jan., 1994, Naval Postgraduate School, Monterey, California.
- N. A. Riza, “Liquid crystal-based optical controllers for phased array antennas,”Optoelectronic Signal Processing for Phased Array Antennas IV Conference Proceedings of the SPIE, Vol. 2155, pp. 169-180 , Jan., 1994.
- N. A. Riza, “Advanced optical techniques for phased array antenna control using liquid crystal display (LCD) technology,” in Workshop Digest on Optoelectronic Technology for Future Navy Active Array Radar, Sept.8, Crystal City, VA, 1994.
- N. A. Riza, “Polarization-based Fiber-optic Delay Lines,”SPIE Conference Proceeding on Optical Tech. for Microwave Appl. VII, Vol.2560, pp.120-129, July 1995.
- N. A. Riza and S.E. Saddow, “N-bit optically controlled microwave signal attenuator using the photoconductive effect,” SPIE Proc., Vol. 2560, pp.9-18, 1995.
- N. A. Riza and N. Madamopoulos, “Photonic time delay beamforming architectures using polarization switching arrays,” SPIE Proc, Vol. 2754, pp.186-197, Orlando, April, 1996
- N. A. Riza, “Advances in Three Dimensional Reversible Photonic Modules for Phased Array Control,” SPIE Proc. Vol.2844, No.35, Denver, August 1996.
- N. Madamopoulos and N. A. Riza, “Switched Three Dimensional Photonic Delay Line using Directly Modulated Semiconductor Lasers for Microwave Radar Processing,” SPIE Proc., Vol. 2845, No. 32, 1996.
- N. A. Riza, “Photonic Control of Phased Arrays using Analog Vector Modulation,’’IEEE Phased Array Antenna Symp., Boston, Oct., 1996.
- N. A. Riza, “Maximum hardware compression reversible photonic beamformer for wideband phased array systems,” OSA Ann. Meeting, Symp. on Optics for RF and Microwave Appl.,Paper ThQQ6, Oct.,24, Rochestor, 1996.
- N. A. Riza and N. Madamopoulos, “ Ternary switched photonic delay lines for rf and microwave array signal processing,” OSA Ann. Meeting, Symp. on Optics for RF and Microwave Appl.,Paper ThQQ7, Oct.,24, Rochestor, 1996.
- N. A. Riza and N. Madamopoulos, “ Phased array radar control using ferroelectric liquid crystal devices,” IEEE LEOS Ann. Mtgs. Digest, OC3: Microwave Systems,Nov.20, 1996.
- N. A. Riza, “Advanced Novel Photonic Instrumentation for Adaptive and Interferometric Astronomy,” SPIE Space Telescopes and Instruments II Conf. Proc., Vol.2807, No.37, Aug.6-7, 1996.
- N. A. Riza, “Coherent techniques and deformable-mirror device (DMD)-based switched photonic time delay control for high frequency antenna arrays,” SPIE Conf. on Optical Technology for Microwave Applications VIII, Vol.3160, pp.97-105, San Diego, August 1997.
- N. Madamopoulos and N. A. Riza, “Adaptable delay balanced loss switched photonic time delay modules for antenna arrays,” SPIE Conf. on Optical Technology for Microwave Applications VIII, Vol.3160, pp.62-68, San Diego, August 1997.
- N. Madamopoulos and N. A. Riza, “ Switched photonic delay line for phased array antenna control using externally modulated microwave fiber-optic link,” SPIE Conf. on Optical Technology for Microwave Applications VIII, Vol.3160, pp.45-55, San Diego, August 1997.
- N. A. Riza and N. Madamopoulos, “ All-fiber connectorized fiber-optic delay module using 3-D polarization optics,” IEEE LEOS Ann. Mtgs. Digest, Vol.2, ThW2, pp.472-473, Nov., 1997.
- N. A. Riza and N. Madamopoulos, “Single micro-optical bench fiber connectorized delay module using bulk polarization optics,” The 8th Ann. DARPA Symp. on Photonic Systems for Antenna Applications, Post-deadline Paper, pp.1-5, Jan. 1998.
- N. Madamopoulos and N. A. Riza, “Photonic delay lines using polarization selective holograms for optical signal routing,” SPIE Conf. Advances in Optical Information Processing VII , Vol. 3388, 16, April 1998.
- N. Madamopoulos and N. A. Riza, “ Reversible fiber-optic switched delay module using GRIN lens fiber-optic collimators and ferroelectric liquid crystals,” IEEE LEOS Ann. Mtgs. Digest, Dec., 1998.
- N. Madamopoulos and N. A. Riza, “ First 7-bit True Time Delay Photonic Controller for a Phased Array Radar,” OSA Ann. Meeting, Symp. on Photonics for RF and Microwave Applications, Baltimore, Oct. , 1998.
- N. A. Riza, Guest Editor Special Issue of the SPIE Optical Processing Working Group NewsLetter on the Topic Photonics and Phased Array Systems (PAPAS), Vol.10, No.1, April 1999.
- Z. Yaqoob, S. A. Khan and N. A. Riza, “Microwave and Optical Beam Control Using JOP Devices,” US-Japan Joint Optoelectronics Project (JOP) Participants Workshop, Hawaii, April 19-20, 2001.
- N. A. Riza and S. A. Khan, “Photonic beamformer with flexible interface for phased array antennas,” in IEEE LEOS 14th Annual Meeting, San Diego, CA, Vol. 2, pp. 816-817, Nov. 2001.
- N.A. Riza, “ Intelligent Light for Signals,” ICO Prize Invited Paper, ICO XIX Conference Digest, SPIE Proc., Florence, Italy Aug. 2002.
- N. A. Riza, S. A. Khan and M. A. Arain “Flexible beamformer and remoting head for optically controlled phased array antennas”, Paper No. TH4D-2, Special Session on Optical Processing of Antenna Signals, IEEE MTT-S International Microwave Symposium Digest, Vol. 3, Page 1941-1944, June 2-7, 2002.
- N. A. Riza, “Fault-Tolerant Multi-Beam Photonic Beamforming for Wideband Array Antennas,” SPIE Photonics North Conference, Paper 101-143, May 26-29, Montreal, Canada, 2003.
- N. A. Riza, “High Speed Multi-Beamforming for Wideband Phased Arrays,” IEEE Microwave Photonics Topical Meeting, MWP 2003, Budapest 2003.
- N. A. Riza, “Hybrid Photonic Signal Processing for Radio Frequency Signals,” Integrated Optics-Theory & Applications (IOTA), Editor, Tadeusz Pustelny, SPIE International Congress on Optics and OptoElectronics, Warsaw, Poland, Aug. 2005.
- N. A. Riza, “ Flexible Agile Hybrid Optical-RF Antenna System for Communications and Radar,” 19th IEEE International Conference on Microwaves, Radar & Wireless Communications, Warsaw, Poland, May 23, 2012.
- N. A. Riza, “Smart Optical Beamforming for Next Generation Wireless Empowered Communications, Power Transfer, Sensing and Displays: Building on the Past,” IEEE ISSC Conference Proc. paper, June 9-10, Cork, Ireland, 2022.
Radar Signal Processing, Filtering and Electronic Warfare Receivers
Journal Publications:
- N. A. Riza, “Optically efficient interferometric acousto-optic architecture for spectrum analysis,” Applied Optics, Vol.31, No.17, pp.3194-3196, June 10, 1992.
- N. A. Riza, “In-line interferometric time integrating acoustooptic correlator,”Applied Optics, Vol.33, No.14, pp.3060-3069, May 10, 1994.
- N. A. Riza, “Space Integrating Interferometric Acousto-optic Convolver,” IEEE Photonic Technology Letters, Vol.7, No.3, pp. 339-341, 1995.
- N. A. Riza, “25-Channel Nematic Liquid Crystal Optical Time Delay Unit Characterization,” IEEE Photon. Tech. Letters, Vol.7, No.11, pp.1285-1287, Nov., 1995.
- N. A. Riza and Sarun Sumriddetchkajorn, “Fault tolerant polarization insensitive photonic delay line architectures using Two Dimensional Digital Micromirror Devices,” Optics Communications , Vol. 160, pp.311-320, 15 Feb., 1999.
- N. A. Riza, M. A. Arain, and S. A. Khan, “Analog-Digital Variable Fiber-Optic Delay Line,” IEEE/OSA Journal of Lightwave Technology, vol.22, No.2, pp.619-624, Feb. 2004.
- N. A. Riza, “Acousto-Optically Switched Optical Delay Lines ,” Optics Communications , Vol.145, pp.15-20, Jan.1, 1998.
- N. A. Riza, “Acousto-Optic Device-based High Speed High Isolation Photonic Switching Fabric for Signal Processing,” Optics Letters ,Vol.22, No.13, pp.1003-1005, July 1, 1997.
- N. A. Riza and S. Sumriddetchkajorn, “Micromechanics-based wavelength-sensitive photonic beam control architectures and applications,” Applied Optics, Vol. 39, No. 6, pp. 919-932,20 Feb. 2000.
- N. A. Riza and M. A. Arain, “Programmable Broadband Radio-Frequency Transversal Filter with Compact Fiber-Optics and Digital Microelectromechanical System-Based Optical Spectral Control,” Applied Optics, Vol.43, No.15, pp.3159-3165, May 2004.
- M. A. Arain and N. A. Riza, “ Optoelectronic approach to adaptive radio frequency transversal filter implementation with negative coefficients by using optical spectrum shaping,” Applied Optics, Vol.45, No.11, 10 April 2006.
- N. A. Riza and F. N. Ghauri, “Compact Tunable Microwave Filtering using Retro-Reflective Acousto-Optic Tunable Filtering and Delay Controls,” Applied Optics, Vol. 46, Issue 7, pp. 1032-1039, 2006.
- N. A. Riza and F. N. Ghauri, “High Resolution Tunable Microwave Filter using Hybrid Analog-Digital Controls via an Acousto-Optic Tunable Filter and Digital Micromirror Device,” IEEE/OSA Journal of Lightwave Technology, Vol.26, No.17, Sept.1, pp.3056-3061, 2008.
Conference Publications:
- N. A. Riza and D. Psaltis, “Multiplicative time and space integrating acousto-optic architectures for real-time spectrum processing,”Conference Proceedings of the International Society of Optical Engineering (SPIE), Vol. 827, pp. 235-243, 1987.
- N.A. Riza, “The in-line acoustooptic interferometer as a correlator and spectrum analyzer,” SPIE Annual Meeting Conference Proceeding on Optical Implementation of Information Processing, Vol. 2026, pp. 130-141,July, 1993.
- N.A. Riza, “The in-line acoustooptic interferometer as a correlator and spectrum analyzer,” SPIE Annual Meeting Conference Proceeding on Optical Implementation of Information Processing, Vol. 2026, pp. 130-141,July, 1993.
- N. A. Riza, “Prospects of optical information processing systems – The years 1995 and beyond,” at the OIDA (Optoelectronics Industry Development Association) Optics in Switching & Computing Technology Vision Workshop, Baltimore, May 7-8, 1993.
- N. A. Riza, “Coherent Optical Correlator with Wideband Signal Processing Capabilities,” SPIE’s International Technical Working Group on Optical Processing & Computing Newsletter, Nov., 1993.
- N. A. Riza, “Novel space/time integrating acoustooptic architectures for radar signal processing,”Optoelectronic Signal Processing for Phased Array Antennas IV Conference Proceedings of the SPIE, Vol.2155, pp.413-419, Jan., 1994.
- N. A. Riza, “Acousto-optic Null Steering Adaptive Photonic Processor Architecture for Phased Arrays,” SPIE Proc, Vol. 2754, pp.95-102 Orlando, April, 1996.
- N. A. Riza and M. M. K. Howlader, “ Photonic processor for in-phase and quadrature array signal processing,” SPIE Proc., Vol. 2754, pp.50-64, Orlando, April, 1996.
- N. A. Riza and Dennis R. Pape, “ Photonic Signal Processing for Inverse Synthetic Aperture Radar Imaging,” SPIE Conf. Advances in Optical Information Processing VII , Vol. 3388, 09, April 1998.
- N. A. Riza, “Multi-function Acousto-optic Signal Processor,” SPIE Conf. Advances in Optical Information Processing VII , Vol. 3388, 12, April 1998.
- N. A. Riza, “Photonic signal processing for phased array sensor systems,” IEEE LEOS Ann. Mtgs. Digest, Dec., 1998. (Invited)
- N. A. Riza, M. A. Arain, F. N. Ghauri, “ Tunable Microwave/Millimeter wave transversal filter using retroreflective spatial photonics,” IEEE Microwave Photonics Topical Meeting, MWP 2004, paper 841, Oct.4, 2004.
- N. A. Riza, “Hybrid Photonic Signal Processing for Radio Frequency Signals,” Integrated Optics-Theory & Applications (IOTA), Editor, Tadeusz Pustelny, SPIE International Congress on Optics and OptoElectronics, Warsaw, Poland, Aug. 2005.
- F. N. Ghauri and N. A. Riza,, “Multi-tap RF Transversal Filter using AOTF Double Diffraction,” CLEO 2007, May 8, Paper CTuAA Baltimore.
- F. N. Ghauri and N. A. Riza, “Programmable microwave transversal filter using acousto-optic tunable filtering,” Proceedings of SPIE, Vol. 6572, Paper No. 6572-07, Enabling Photonics Technologies for Defense, Security, and Aerospace Applications, in Defense and Security Symposium 2007, Orlando, Florida, USA , April 09, 2007.
Security and Smart Display Systems
Journal Publications:
- N. A. Riza, M. M. K. Howlader, and N. Madamopoulos, “Photonic Security System using Spatial Codes and Remote Coded Coherent Optical Communications,” Optical Engineering, Vol.35, No.9, pp.2487-2498, Sept., 1996.
- Z. Yaqoob and N. A. Riza, “Eye-safe passive-optics no-moving parts barcode scanners,” IEEE Photonics Technology Letters, Vol.16, No.3, pp.954-956, March 2004.
- N. A. Riza and S. Sumriddetchkajorn, “Micromechanics-based wavelength-sensitive photonic beam control architectures and applications,” Applied Optics, Vol. 39, No. 6, pp. 919-932,20 Feb. 2000.
- N. A. Riza and M. A. Arain, “Code multiplexed optical scanner,” Applied Optics, IP, Vo.42, No.8, March 10, 2003.
- N. A. Riza and P. J. Marraccini, “ Smart Two Dimensional Laser-Based Display,” IEEE Journal of Display Technology, IEEE Journal of Display Technology, Vol.7, No.2, pp.90-95, Feb.1, 2011.
Conference Publications:
- N. A. Riza, “High Speed Wide Bandwidth Optical Encryption and Decryption System using Spatial Codes,” IEEE LEOS Annual Meeting Proceedings, OC 7.4, Nov., 1995.
- N. A. Riza, “Universal Optical Code Division Multiple Access (O-CDMA) Encoders/Decoders,” SPIE Photonics North Conference, Paper 101-513, May 26-29, Montreal, Canada, 2003.
- Z. Yaqoob and N. A. Riza, “Eye-safe passive-optics no-moving parts barcode scanner,” in Photonics, Communications, and Devices, Optics in the Southeast, Orlando, FL, USA, November 12-13 (2003).
- M. A. Arain, N. A. Riza, “High-beamforming power-code-multiplexed optical scanner for three-dimensional displays,” Proc. SPIE Vol. 5243, p. 59-64, Three-Dimensional TV, Video, and Display II; Bahram Javidi, Fumio Okano; Eds., September 2003.
- N. A. Riza and M. J. Amin, “Liquid Lens-based Smart Scanning Laser Projection Display,” 3rd Optofluidics EOS Conference Proc., May, Munich, 2013.
- N. A. Riza, “Smart Optical Beamforming for Next Generation Wireless Empowered Communications, Power Transfer, Sensing and Displays: Building on the Past,” IEEE ISSC Conference Proc. paper, June 9-10, Cork, Ireland, 2022.
Patents – Aerospace and Display Systems
- N.A. Riza, “Reversible time delay beamforming optical architecture for phased array antennas,” U.S.A. Patent No. 5,117,239, May 26, 1992.
- N.A. Riza, “Reversible time delay beamforming optical architecture for phased array antennas,” Europian Patent No. 92303635.4, July 07, 1992.
- N. A. Riza, “Compact wide tunable bandwidth phased array antenna controller,” U.S.A. Patent No. 5,187,487, Feb.16, 1993.
- N. A. Riza, “Phased array antenna controller,” U.S.A. Patent No. 5,191,339, March 02, 1993.
- N. A. Riza, “Time multiplexed phased array antenna beam switching system,” U.S.A. Patent No. 5,231,405, July 27, 1993.
- N. A. Riza, “Optical controller with independent two dimensional scanning,” U.S.A. Patent No.5,274,381, Dec.28, 1993.
- N. A. Riza, “Optical time delay units for phased array antennas,” U.S.A. Patent No.5,274,385, Dec.28, 1993.
- N. A. Riza, “An optically controlled phased array radar,” U.S.A. Patent 5,307,073, April 26, 1994.
- N. A. Riza, “An optical transversal filter,” U.S.A. Patent No. 5,329,118, July 12, 1994.
- N. A. Riza and M. C. DeJule, “High signal-to-noise ratio optical signal processing system,” U.S.A. Patent No. 5,400,038, March 21, 1995.
- N. A. Riza, “Compact optical controller for phased array systems,” USA Patent No. 5,731,790, March 24, 1998.
- N. A. Riza, Hybrid Photonic Signal Processing Modules, USA Patent 8,170,384, May 1, 2012.
- N. A. Riza and F. Perez, Spatially Smart Optical Sensing and Scanning, USA Patent 8,213,022, July 3, 2012.
- N. A. Riza, Compressive optical display and imager, USA Patent 8,783,874, July 22, 2014.