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High-precision imaging technology and its application are highly demanded for the enhancement of civil security. They are used to help prevent major incidents in railways or airports. In these applications, both small object detection and high-range resolution are key features. As far as the detectable target size is concerned, a high-frequency carrier is indispensable in radar systems. However, a...
In this paper we demonstrated 9.978-GHz microwave extraction from a mode-locked Er-fiber laser with −113 dBc/Hz phase noise at 10 kHz offset frequency. Instead of phase locking loop or direct detection, the extraction was achieved by a delay-matched frequency conversion pair and IF-domain opto-electronic conversion and narrowband filtering. Phase noise suppression as large as 32 dB, compared with...
Optical frequency combs from mode-locked lasers are developed and used for realizing unique functionality for applications in ultra-wide bandwidth communication and signal processing.
Commercial-off-the-shelf photonic components designed for datacenter or industrial applications do not typically satisfy the environmental ruggedness requirements of aerospace and military applications. In order to reduce costs and schedule risk for insertion of photonic components into these harsh-environment avionic and vehicle applications, we developed a variety of rugged photonic transceivers...
This paper describes an “active” version of a hermetic fiber-optic feedthrough for avionic transceivers; active means that the Tx and Rx versions of the feedthroughs include a VCSEL array or a photodiode array, respectively. The hermetic feedthrough is an assembly of stamped components that align all of the optics to precision sufficient for single-mode applications. A stamped micro mirror array bends...
An overview of the research and technological development of the fiber-optic sensing system (FOSS) at the National Aeronautics and Space Administration Armstrong Flight Research Center (NASA AFRC) is presented. Theory behind fiber Bragg grating (FBG) sensors, as well as interrogation technique based on optical frequency domain reflectometry (OFDR) is discussed. Assessment and validation of FOSS as...
Detecting and analyzing the spectral content of intercepted microwave and millimeter-wave signals over a very wide bandwidth in real-time and with high resolution is an essential capability in many applications, ranging from commercial and surveillance, to defense. This is typically implemented by dividing the RF spectrum to be analyzed into narrower frequency slices, known as channelizing, which...
Single event effect susceptibility of several commercial optical transceivers were studied. The results and the performances of the transceivers based on Weibull fit are discussed. Based on results, we conclude that commercial components need to reinforce in order to be suitable for space application.
A high performance liquid-level sensor based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported in detail. The sensor sensitivity is found to be 98pm/cm of liquid, enhanced by more than a factor of 9 compared to a reported silica fiber-based sensor.
Demonstration of low conversion loss through the novel integration and packaging of high power photodiodes and a fragmented aperture antenna for a fiber-fed RF array.
Freedom Photonics has demonstrated a semiconductor modulator with 1.2V static Vπ and >20 GHz bandwidth, and photodetectors that operate linearly up to 100mA photocurrent and with a bandwidth exceeding 20 GHz. These components will form the basis for high performance RF photonic links with low noise figure, high SFDR and realistic operating optical power in the 100's mW range.
Free-space optical networks have serious block erasures due to atmospheric turbulence and require an entirely new network architecture from Layer 1 to Layer 4 for big data flows.
In summary, the investigation shows the temperature sensitivity of the POF splices restricted their use specifically to non-critical applications. However, avionic POF splice can be realized in the future with suggested modification.
Microwave photonics (MWP) is an emerging field in which the radio signals are generated, distributed, processed and analysed using the strength of photonics. It is a disruptive technology which enables various functionalities which are not feasible in only the microwave or electronic domain. A particular aspect that has gained a significant interest recently is the use of photonic integrated circuit...
An integrated tunable MSM PD based on Indium Tin Oxide (ITO) that is fabricated on Si and InP. Tuning is achieved by thermally controlling the bandgap of the semiconductor using a Nickel Chromium (NiCr) microheater.
Sandia's broad national security mission has supported novel optoelectronics and integrated photonics R&D and technology transfer for over 30 years. Examples of this history, current capabilities, and potential future directions will be discussed.
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