We present a pulsed fiber laser for automotive LIDAR, which is suitable for production at a scale of millions of units per year. The laser maintains >8% true wall-plug efficiency over an extremely wide temperature range and high reliability for lifetime more than 10 years.

We present a high-power DFB technology that meets the performance and volume demands of consumer automotive applications. Our DFB design is hardened and intended for use at extreme environmental conditions and operates at peak current density of 8 kA/cm2 - approximately 4 times higher than more conventional DFB lasers intended for use in telecommunication and sensing applications. We demonstrate that the risks associated with placing these components into high volume production with high yield can be managed through careful control of the laser design and manufacturing processes. To date, we show >90% of our DFB lasers fall within our control limits as defined by three sigma of the mean. This is the first high-power DFB laser suitable for widespread deployment into the consumer automotive market space.

This talk will describe how innovations starting from a “chip level up” component innovation strategy drives system design, architecture choices and industrialization processes to fuel a technological paradigm shift in 3-D sensing. These innovations are enabling some of the biggest industries in the world, including transportation, aviation and smart cities. As an industry we are just in the early stages of unlocking the potential of lidar technology and will to unlock the next generation of vehicle safety and automated driving capabilities. This talk will discuss these innovations and discuss how lidar technology is transforming entire industries today and why there’s no sign of slowing down.

We demonstrate a single mode fiber-coupled packaged semiconductor optical amplifier delivering >30 dBm of continuous wave ex-fiber power at 1550 nm. This is the world's first watt-class c-band fiber-coupled semiconductor optical amplifier and may displace erbium doped fiber amplifiers in applications including optical communication and LIDAR.

As prevalence of dental caries in children rises worldwide, there is an increasing need for a safe, easy to use and cost-effective technique to detect and identify childhood caries at an early stage where remineralization of the tooth is possible and damage may be reversed. We have developed a simple and robust autofluorescence (AF) laboratory device that uses the dental AF spectra from 405 nm and 532 nm laser excitation and computes a ratio of the integrated areas of the spectra. Ten human extracted teeth with early stage natural caries lesions and an additional 8 human extracted teeth with artificially created erosion lesions were used for the study. The 405/532 nm AF ratio was obtained from healthy as well as unhealthy enamel regions for all teeth. A clear distinction between the ratios for healthy enamel and unhealthy enamel was seen. A percent change in 405/532 nm AF ratio of 62% was seen between natural white spot lesions and healthy enamel, with progressively more severe lesions leading to greater percent changes in AF ratios. The 405/532 nm AF ratio is a promising technique that may be used to detect the presence of early stage dental caries and triage high risk children. A cost effective clinical device can be developed which utilizes the proposed technique to screen children in underserved communities.

The lithographically patterned dichroic filter arrays (DFAs) is a new approach to multispectral imaging. The DFA technique offers simultaneous spectral and spatial imaging at a significant cost, size, and complexity advantage over conventional hyperspectral imagers.

Spectrometer system designs have evolved rapidly over the last decade after a major paradigm shift occurred as spectroscopy systems advanced from bulky lab based instruments to the modern compact, flexible, and portable instruments we see today. Previously, these complicated tabletop laboratory instruments required controlled conditions to function and were extremely expensive. That changed with the introduction of compact fiber coupled microspectrometers that combined innovative compact designs with low-cost detectors developed for high volume commercial applications. The miniature spectrometer dramatically broadened the applications and markets for spectroscopy. No longer did users have to carry the sample to the spectrometer, now they could take the spectrometer to the sample enabling thousands of new applications. Over time, the performance and benefits of these compact systems have improved. The recent development of CMOS sensors and imagers and extremely powerful compact microprocessors has enabled a new phase of even more compact spectroscopy systems.

The sequential rotating filter wheel is a new approach to multispectral imaging, which offers HDTV quality images with on board data processing and display at a significant cost and size advantage over conventional hyperspectral imagers.

Spectral imaging involves capturing images at multiple wavelengths resulting in a data cube (x, y, λ) that allows materials to be identified by its spectral signature. While hyperspectral imagers can provide high spectral resolution, they also have major drawbacks such as cost, size, and the copious amounts of data in the image cube. Typically, the complete hyperspectral data cube provides little additional information compared to only 3-8 discrete (multiwavelength) imaging bands. We present two new approaches and related technologies where we are able to acquire spectral imaging data stacks quickly and cost-effectively. Our two spectral imaging systems represent different approaches integrated with standard CCD and CMOS imagers: sequential rotating filter wheels (RFWs) and lithographically patterned dichroic filter arrays (DFAs). The RFW approach offers the ability for rapid configuration of a spectral system, and a whole new level of self-contained image acquisition, processing and on-board display. The DFA approach offers the potential for ultra compact imagers with acquisition of images of multiple wavelengths simultaneously, while still allowing for processing and display steps to be built into the camera. Both approaches lend themselves production of multi-wavelength/spectral imaging systems with differing features and advantages.

Until recently optical coatings have been one area that existed primarily in the macro realm. Entire optical surfaces could be coated quite easily with various thin film optical coatings. However precise deposition of patterned optical filter coatings was limited by the use of metal masking. Similarly, the dicing and bonding of individual filters together to form an assembly is a tedious process, with miniaturization limited by handling and dicing constraints. We are reporting on a new class of lithographically patterned dielectric thin film coatings that enables precision placement and patterning of dichroic and multilayer thin film coating features on a single substrate down to the micron scale. Because the process relies on precision microlithography instead of cut metal masks to pattern the deposited coatings, features (coated areas) as small as 5 microns can be produced, with spatial registration to adjacent coated areas within 1 micron. Furthermore, we report on new developments which involve patterning optical thin film filter on active photodetector substrates. The possibility of now using active devices with patterned dielectric optical filter arrays opens up a wide landscape of new opportunities in solid-state spectral sensing, from more precise color detection to enhanced multispectral imaging.

Multispectral imaging or imaging spectroscopy obtains spectral content of an object by dividing the image data, pixel by pixel, into wavelength (color) bands. The resulting 3D data cube (x, y, λ) allows materials to be identified by their pixel spectral content at multiple wavelengths in addition to their spatial characteristics. A new class of multispectral imaging systems are being developed that utilizes lithographically patterned dichroic filter arrays integrated with standard CCD and CMOS detector arrays. These new imagers offer the unique advantage of scalability to tens of Megapixel resolutions, compact size, and no moving parts. Our multispectral imagers are much simpler to manufacture in volume because the complexity is in the lithographically patterned dichroics rather than in the bulk optical system. The patterned dichroic filter arrays are fabricated utilizing standard microlithography techniques and can incorporate up to 10 different wavelength bands deposited onto a single substrate. Each channel is selectively patterned on the substrate with the dichroic filter coating applied using standard thin film coating techniques. The technique is repeated for all of the wavelength bands and then the final filter array is directly attached and aligned onto the CCD.

Using a Gaussian-to-flattop beam reshaper and a frequency-doubling crystal, we demonstrate highly efficient and spatially uniform pulse compression of 1-mJ, ~100-fs pulses from a regenerative Ti: Sapphire amplifier.

In this talk we will present an overview of recent development of ultrafast lasers sources and their applications. This talk will highlight some recent state of the art ultrafast pulse results from Ti:Sapphire and Ytterbium based laser systems. There are significant advantages in being able to directly diode pump Ytterbium materials resulting in more compact bulk solid state and fiber based laser systems. Several newly emerging technologies such as Optical Parametric Chirped Pulse Amplification, and Supercontinuum Generation have generated great excitement in recent years. The evolution of more compact and user friendly ultrafast laser systems has enabled completely new fields that take advantage of the extremely high peak powers and very short time duration of ultrafast laser pulses. Recent results in the fields of multiphoton microscopy, micromachining, 3-D fabrication, and spectroscopy will be discussed.