- Front Matter: Volume 9467
- Keynote Session
- Flexible, Stretchable, Transient Electronics: What's Next?
- Low-Intensity Energy Delivery for Biomodulation I
- Low-intensity Energy Delivery for Biomodulation II
- Beyond Graphene Layered Materials and Devices
- Graphene and 2D Electronics and Optoelectronics
- Surface Enhanced Spectroscopies for Ultrasensitive Sensing
- Novel Nanophotonic Devices, Sensors, and Concepts Based on 2D Materials
- Origami: Where Art, Devices, and Structures Merge
- Micro- and Nano-Sensors and Materials for Oil and Gas Applications
- Novel Harsh Environment Sensors for Energy Applications: Joint Session with Conferences 9467 and 9491
- MAST: Bio-inspired Control: Joint Session with Conferences 9467, 9468, 9479
- MAST: Scale Legged Locomotion: Joint Session with Conferences 9467, 9468, 9479
- Novel Beam Control Applications and Techniques
- Photonics Research at SPAWAR
- Ultra-fast Bandgap Photonics
- THz Photonics
- Mid-IR Laser Photonics
- Laser Chemical Detection: Joint Session with Conferences 9467, 9455, 9486
- Poster Session
The development of advances in surgical techniques and pharmaceuticals have dramatically contributed to the improvement of global health. However, surgical procedures and pharmaceutical agents are costly and have the potential to create severe side effects and complications for patients. Interdisciplinary researchers are looking for non-pharmaceutical therapies and non-surgical interventions to provide effective treatment for a broad range of medical conditions. This presentation describes one of the most promising therapies-photobiomodulation.
After more than fifty (50) years of clinical use, no serious side effects or adverse reactions of using phototherapy as a medical treatment modality have been observed. Phototherapy affects the natural and basic mechanism of virtually all human cells and restores impaired function, triggering a subsequent cascade of positive therapeutic effects.
Phototherapy currently is being used in virtually every medical specialty including dermatology, plastic surgery, family medicine, vascular surgery, thoracic surgery, ophthalmology, ENT, gastroenterology, hematology, oncology, orthopedics, endocrinology, esthetics, urology, neurology and neurosurgery to name a few. In general, phototherapy serves to improve wound healing, cellular function, reduction of edema, healing of neurological injuries, increased microcirculation and provides intrinsic pain relief. More than 3,000 scientific archived references by the Swedish Laser Society report restorative, therapeutic and healing results from the use of photobiomodulation therapy.
As with all types of scientific work, new discoveries generate new questions. In spite of tremendous advances in the scientific understanding of the medical effects of light we still do not know all the optimal parameters. We also are still struggling as clinicians and scientists to understand the scientific term which best describes the medical effects of light on the modulation of human cell function.
Despite the fact that we are still learning the pathophysiology every day and searching to find the terminology to describe the effects that we are observing it is important to know that clinicians and researchers alike know enough to make phototherapy a mainstream clinical treatment modality. The application of phototherapy inducing photobiomodulation effects has changed the lives of hundreds of thousands of patients and will continue to grow as our understanding of the healing abilities of the application of light continues to improve.
Conversion of plane waves to surface waves prior to detection allows key advantages in changes to the architecture of the detector pixels in a focal plane array. We have integrated subwavelength patterned metal nanoantennas with various detector materials to incorporate these advantages: midwave infrared indium gallium arsenide antimonide detectors and longwave infrared graphene detectors.
Nanoantennas offer a means to make infrared detectors much thinner by converting incoming plane waves to more tightly bound and concentrated surface waves. Thinner architectures reduce both dark current and crosstalk for improved performance. For graphene detectors, which are only one or two atomic layers thick, such field concentration is a necessity for usable device performance, as single pass plane wave absorption is insufficient. Using III-V detector material, we reduced thickness by over an order of magnitude compared to traditional devices.
We will discuss Sandia’s motivation for these devices, which go beyond simple improvement in traditional performance metrics. The simulation methodology and design rules will be discussed in detail. We will also offer an overview of the fabrication processes required to make these subwavelength structures on at times complex underlying devices based on III-V detector material or graphene on silicon or silicon carbide. Finally, we will present our latest infrared detector characterization results for both III-V and graphene structures.
Advances in infrared (IR) detector technologies over the last decade have led to compact low-cost thermal imaging systems that have become almost ubiquitous. They are now used in such market applications as automotive, security and construction. Terahertz (THz) imagers can take advantage of the state-of-the-art in the infrared domain to reduce their size and cost. Such an example is the IRXCAM-THz-384 Terahertz camera whose electronics core is based on the IRXCAM camera core and whose detector has been specifically designed and optimized for the THz. The 384 x 288 35- micron-sized pixel detectors of both cameras are uncooled microbolometers. A micro-electronics core is currently being developed for both platforms that will yield ultra-compact IR and THz cameras.
While IR systems are passive and thus do not require an illumination source, the THz system does. Thus, the THz source must be included when talking about overall imaging system size and cost. There are a wide variety of THz sources, from quantum cascade lasers on the optical side of the radiation spectrum to different types of diodes on the electromagnetic micro-wave side. When considering a source for a given application, the output wavelength, output power, size, weight and cost are primary factors that must be taken into account.
This paper presents a description of a compact real-time imaging system at 750 μm wavelength. An overview of the motivation for the wavelength choice is discussed, a description of the imaging components is given and finally image results are presented.
A microstructure along with a robust fabrication process is developed for measuring the thermal conductivity (K) of nanowires and thin films. The thermal conductivity of a thin-film material plays a significant role in the thermoelectric efficiency of the film and is usually considered the most difficult thermoelectric property to measure. The lower the K, the higher is the thermoelectric efficiency and hence a higher detectivity can be attained if utilized for infrared detection. We have previously shown high responsivity uncooled thermoelectric IR detectors [1] that utilize polysilicon as the thermoelectric material. To further improve the performance of these devices, it is required to understand how the wire dimensions and different deposition parameters affect the thermal conductivity of polysilicon.
The nanowires of this work are formed by patterning a thin layer of low-pressure chemical vapor deposited polysilicon using e-beam lithography. Consequently, the common pick-an-place process followed by deposition of metallic contacts is avoided. As a result a significant source of error in calculating the thermal conductivity is eliminated. Additionally, several serpentine nanowires are fabricated between the two thermally-isolated membranes so that a greater amount of heat, comparable to heat loss through the arms, is transported through the nanowires for a more accurate measurement while the serpentine shape of the wires improves their structural integrity. The K of polysilicon nanowires are measured for the first time and it is shown that for nanowires with a cross section of ~60nmx100nm, the K is ~3.5 W/m.K (a 10X reduction compared to the bulk value of ~30W/m.K [2]).