JAMES P. SIEPMANN AND ADAM RYBALTOWSKI
Clock
Electrical pulse generator/driver
Mirror driver
λ/2 Polarizing λ/4 plate beamsplitter plate
Laser
Collimating lens
MEMS mirror (2-axis)
Bandpass filter Transmitted
Real-time digitizer
with peak and
time-interval
analysis algorithm
Focusing signal lens
AReflected signal lthough laser radar (ladar) has Photo- been actively pursued by the mil- Amplifier detector Target itary and civilian industries for FIGURE 1. A next-generation scanning 3-D real-time ladar is built decades, only recently have the around a scanning MEMS mirror. techniques of optically extending
the scanning range of microelectro- The scanning range of a The major barriers to expansion mechanical-systems (MEMS) mir- of 3-D real-time ladar are weight rors made miniaturization of 3-D MEMS mirror can be increased and cost—the smallest existing real-time ladar possible. This next- device weighs more than 15 kg generation 3-D ladar will be highly by adding optics that amplify and the average cost for 3-D accurate, economical, eye-safe, and ladar units is about $100,000.1 small enough to hold in one’s hand. the scanning angle. This
Today’s scanning 3-D ladar can Next-generation
have greater angular, range, and ul- “optical extension” technique scanning ladar
timately better display resolution The next-generation scanning
than alternative imaging techniques. allows miniaturization of 3-D ladar systems will likely use
It can be used to “see” targets that 3-D real-time imaging ladar a pulsed time-of-flight methodol- are invisible to other imaging de- ogy and consist of a clock, pulse
vices and has already found many systems to a size that opens generator/driver, laser, scanning
practical applications. Unlike 1-D MEMS mirror(s), transmitting/
ladar, which is currently being used up many new applications. receiving scanners, photodetector,
by law enforcement to catch speed- and data-acquisition electron-
ers, 3-D imaging ladar is being used ics (see Fig. 1). The data obtained
for target identification, terrain mapping, 3-D documen- from the ladar device can then be visually displayed for the
tation of buildings/objects, robotic navigation, and more. user and/or wirelessly transmitted to a data-collection com-
puter for more in-depth processing. A potential example of
the latter would be multiple soldiers at different locations
JAMES P. SIEPMANN is a founder and chief research officer and ADAM RYBALTOWSKI is an electro-optics engineer at Light Time, 375 who would use GPS (global-positioning-system) integrated City Center, Suite Q, Oshkosh, WI 54901; e-mail: mail@Light Time.com. ladar to scan the same field of combat. These multiple in-
References:
http://www.laserfocusworld.com
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