Pile B.C.,University of Connecticut |
Pile B.C.,ODIS , Inc. |
Taylor G.W.,University of Connecticut |
Taylor G.W.,ODIS , Inc.
Journal of Lightwave Technology | Year: 2012
We analyze the operation and performance of subsampled analog optical links. These links downconvert microwave signals by optically sampling at a rate much lower than the RF carrier frequency. Expressions for conversion gain, noise figure, and spurious-free dynamic range are derived for intensity modulation and direct detection. The impact of pulse width on link performance is revealed and quantified. Also, in order to characterize noise in a subsampled link, the influence of timing jitter in the periodic optical source is considered. Timing jitter and pulse width are found to be two important factors which limit the noise figure and dynamic range in subsampled links. © 2012 IEEE.
Zhang Y.,ODIS , Inc. |
Taylor G.W.,University of Connecticut
Advances in OptoElectronics | Year: 2013
A novel electronically tunable optical delay line based on InGaAs quantum well microresonators is proposed for high frequency RF transmission. The device utilizes the charge-controlled blue shift of the absorption edge in InGaAs quantum wells to change the effective refractive indices of the resonators and couplers, therefore, provides an efficient way to produce variable time delay. A theoretical model based on measurements is used to analyze the device performance. Simulation results for five 3 × 27 μm2 cascaded resonators with bias voltages <0.7 V show a continuous tuning range of 7∼68 ps, a ripple delay <1.5 ps, and a useable bandwidth of 39.3 GHz. © 2013 Yan Zhang and Geoff W. Taylor.
Yao J.,University of Connecticut |
Cai J.,ODIS , Inc. |
Opper H.,ODIS , Inc. |
Taylor G.W.,University of Connecticut
IEEE Photonics Technology Letters | Year: 2011
An optically active heterostructure field effect transistor (HFET) structure is described as a three terminal detector. With an in-plane waveguide optical input it demonstrates natural optoelectronic integration with transistors. Both depletion and enhancement threshold devices are realized with photocurrent enhancement of the HFET current of 1.72 for direct coupling. A simple model of photocurrent generation based on bipolar operation provides good agreement. The bidirectional response may be suitable for optical gating functions in balanced detection. © 2011 IEEE.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 99.89K | Year: 2010
The digital signal processing and static memory is currently dominated exclusively by CMOS technology with the 6-T cell implementing all static memory. CMOS is the only VLSI technology. However, CMOS is near the end of its scaling potential and it has a severe liability for space applications due to a weakness to radiation. Further, the 6T cell is relatively area and power consumptive and falls well short of the requirements for next generation satellites. ODIS proposes an optoelectronic solution based upon a monolithic technology platform for O and E devices. A key element in the device group is the thyristor which has both laser and detector functions. The thyristor has a very low power storage mode that enables a single device memory cell that may be dynamic or a static memory cell. The dynamic version offers the lowest possible power of any known semiconductor memory. Both the read and write operations are performed optically with on-chip light sources enabling very high speed and high density memory arrays. In addition to the ultra-low power memory , the thyristor also enables a low power logic gate. In this SBIR, ODIS will demonstrate the first integrated low power dynamic ram and logic cell BENEFIT: The digital processor market is several billion dollars with steady growth potential based upon an expending PC industry. As CMOS is constrained by power and speed , the opportunity for GaAs based circuits is significant. The wireless industry is already using all of the GaAs amplifiers that are produced. One can therefore expect a market opportunity for GaAs based memory products with large up-side potential. Digital products can now be added to a growing number of markets addressed by integrated optoelectronics including AD converters, imager products, parallel optical data links, optical interface circuits, phased array receivers and other markets currently dominated by Si.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.90K | Year: 2010
IR imagers currently require hybrid read-out integrated circuits (ROIC’s)and additional separate AD converters (ADC) to provide transmittable data formats to digital signal processors (DSP’s). The DSP is currently dominated exclusively by CMOS technology as the only high density low power technology. New capabilities for IR imaging based on GaAs are being developed which have the potential for monolithic ROIC’s. However the advantage of the monolithic pixels increases enormously if digitization could also be realized within the chip. To this end, a special requirement is to develop and optimize the IR pixel simultaneously with the ADC. ODIS has identified a unique opportunity to implement novel multi-wavelength pixel designs together with a ÓÄ ADC in which the true ÓÄ performance can only be realized with a high speed decimator. At 60GB/s bit rates, the only solution to the decimator is EO logic. The pixel response is based upon intersubband absorption with CCD read-out transfer. The EO logic is based upon the unique thyristor properties. The combination of these functions monolithically will result in unrivalled IR capability. In this project, ODIS will optimize the pixel response and readout amplifiers in a planar technology platform that supports the EO logic needed for the decimation. BENEFIT: The digital processor market is several billion dollars with steady growth potential based upon an expanding PC industry. The IR imager market will realize huge growth with the availability of monolithic pixel and ROIC combinations. A market opportunity thus exists to produce IR imagers supported by EO logic circuits. The market share for GaAs based digital products in the multi-GB/s range will expand dramatically. Digital and imaging products can now be added to a growing number of markets addressed by integrated optoelectronics including parallel optical data links, optical interface circuits, phased array receivers and other markets currently dominated by Si.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.97K | Year: 2010
Optical switching fabrics describe arrays of interconnected optical switches that enable input signals to be directed to output ports with optimal flexibility. Such arrays avoid the use of OE conversions and circuit-switched connections by allowing the optical data stream to pass through the fabric in its original form. As such, the fabric requires very dense, low loss switches with high speed reconfigurability. Such arrays can be realized with an MEMS mirror arrays, electro-optic (EO) (8x8 LiNbO3 demonstrated) , interferometric, digital optical, liquid crystal, bubble, acoustooptic and semiconductor amplifier switches. However currently all routing is done with circuit switching. The issues are insertion loss, crosstalk, extinction ratio, polarization dependence and scalability. For high speed operation the EO switch must be used and for integration only the semiconductor approach is viable. ODIS proposes a semiconductor directional coupler that can be scaled to lengths
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 749.91K | Year: 2012
Optoelectronic integrated circuits offer radiation-hard solutions for satellite systems with much improved SWPB (size, weight, power and bandwidth). The phased array for sensing and data transfer is one system that optoelectronics can impact in the near term. It is known that optical delay could enable optimum beam steering electronic scanning . Lidar is another sensing system using optical beams that requires mechanical steering. In this SBIR a new integrated circuit technology is applied to the RF array with true time delay for beam steering and combined in the same physical location with an optical beam steered via current control. The integrated components required are lasers, amplifiers, modulators, detectors and optical waveguide switches. The RF at Ka band is generated by an optoelectronic oscillator and converted to RF power in a photodiode at the antenna element. The antenna element is a printed dipole on chip with optimized dimensions Ka band operation. The optical source is an array of vertical cavity lasers closely spaced and coupled by anti-guiding to enable coherent operation. Optical beam steering is achieved by controlling the current in a 2D array. In this SBIR, ODIS will develop the key components integration to produce common RF/optical aperture operation.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 99.99K | Year: 2011
Optoelectronic integrated holds the key to higher performance, reduced mass and radiation-hard space systems. A special need is increased flexibility of phased arrays for communication and detection. Currently RF arrays use ferrite waveguide elements for phase shifting which are both bulky and lossy with a phase shift limit of 360Âº . Light Detection and Ranging (LIDAR) arrays currently use a single optical source with mechanical steering. An identified goal would be an RF array with true time delay for beam steering and combined in the same physical location with an optical array steered via optical phase shift. ODIS approaches this problem with an optoelectronic circuit that integrates the RF and optical elements within a single chip. The RF at Ka band is generated by an optoelectronic oscillator and converted to RF power in a photodiode at the antenna element. The antenna element is a printed dipole on chip with dimensions of & #955;/2 ( & #8776;4.3mm). The optical source is an array of vertical cavity lasers spaced sufficiently closely to achieve a coherent beam. Optical beam steering is achieved by optical phase shifting of the coherent beam. In this SBIR, ODIS will demonstrate the key components integration to achieve a common RF/optical aperture.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.94K | Year: 2010
CDMA is a successful network technology for the wireless industry which relies totally on conventional integrated circuits. The same architecture is equally appealing for telecommunications and is considered an optimum choice for next generation FTTH networks if only low cost implementations were available. The persistent high costs are driven by disparity between optical and electrical components which include WDM capability on the one hand and digital processing on the other. What is required is the ability to merge these onto a single integrated platform so that signals could remain optical at high speeds right to the point that OE conversion was essential. With both capabilities on one die, cost goes down and performance goes up. These same attributes apply to airborne communications. The security enabled is a key aspect and thus multiple recent efforts have focused on the addition of existing PIC devices to a standard CMOS platform. ODIS offers a different solution in the form of POET, a III-V complementary HFET technology on the same integrated circuit as the wavelength division components for OCDMA. This approach achieves the goal and has already solved the main issue of technology compatibility. In this SBIR , POET will be demonstrated for OCDMA.
ODIS , Inc. | Date: 2010-01-28