Dr. Brian Saar (saar@ll.mit.edu)

AAAA Aircraft SurvivabilityEquipment Symposium

14 November 2017

Advanced Technology Development at MIT Lincoln Laboratory

Delivered to the US Government with Unlimited Rights, as defined in DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any copyright notice, U.S. Government rights in this work are defined by DFARS 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work other than as specifically authorized by the U.S. Government may violate any copyrights that exist in this work.

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© 2017 Massachusetts Institute of Technology.

This material is based upon work supported by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Assistant Secretary of Defense for Research and Engineering.

BGS - 214 November 2017

MIT Lincoln LaboratoryDoD Federally Funded Research and Development Center

Massachusetts Institute of Technology MIT Lincoln Laboratory, Lexington, Massachusetts

Mission: Technology in Support of National Security

Key Roles: System architecture engineeringLong-term technology developmentSystem prototyping and demonstration

Air and MissileDefense

HomelandProtection

Air TrafficControl

CommunicationSystems

AdvancedTechnology

SpaceControl

ISR Systemsand Technology Tactical Systems

Mission Areas:

Cyber Security

Engineering

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BGS - 314 November 2017

1 m

A “Building Block” Laser Concept Based on Semiconductor Optical Amplifiers

• 1 MW-class over ~1 m2 (100 W/cm2)•1000 x 1000 W

Power Conditioning

Phased Array with Uniform

Top-Hat Profile

Optics array for high fill factor

Phase Control

Thermal Management

3 cm

• Array of ~ 1000 Emitters over ~10 cm2

• MOPA architecture w/seed distribution• 1 W each, pitch ~ 1 mm, ~ 1kW

Wave guide

Turning mirror

SCOWA

Power Conditioning

Power scaling with a modular, agile beam architecture can have a significant Impact on future HEL systems, including expanding the number of subapertures available for atmospheric compensation

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BGS - 414 November 2017

Initial 100 Element Surface Emitting Array Results

Top View

Achieved ~30W/cm2 of raw power in a 2-D array

97 Operational Emitters

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BGS - 514 November 2017

Motivation for Germanium CCD Imagers

SWIR Sensitivity [1-3]

[1] T. Martin & P. Dixon, Laser Focus World (11/2004); [2] MIT-LL measured; [3] average from Nakano et al., J. Non-Cryst. Sol. 358 (2012) 2249 & N. Posthuma et al., Proc. 3rd World Conf. Photo. Ener. Conv. (2003), scaled to 45 µm. [4] M.L. Vatsia (September 1972). Atmospheric optical environment. Research and Development Technical Report ECOM-7023

Disruptive Potential for Imaging in These Bands

Wafer Size Comparison Sensor Size Comparison

200 mm

Germanium

InGaAs (SWIR)InGaAs

(1.3 Mpix)

5 cm

Germanium(> 20 Mpix expected)

• High-quality gate dielectrics enable CCDs

• No bump-bonding required• Compatible with Si CCD tool set

Light levels at night [4]SWIR provides

high signal regardless of

moonlight

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BGS - 614 November 2017

Demonstration of 32 × 32 × 8.1 µm Germanium Imager Array

Optical Micrograph of 32 × 32 Array

100 µm

Dark Response

Red LED Illumination

Subtracted Image

Scale: 4000-8000DN

Scale: -500-2000DN

Scale: 4000-8000DN

Further improvements to isolation led to operable pixel arrays at -60°C

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BGS - 714 November 2017

Simultaneous Transmit and Receive (STAR) Applications

STAR enables concurrent multifunctionality between multiple federated systems sharing a common aperture

Electronic SurveillanceContinuous monitoring of spectrum during transmission.

Advanced CountermeasuresResponsive jamming for improved threat protection

Full Duplex NetworkingIncreased spectral efficiency and network capacity

STAR RadarIncreased sensitivity and lower probability of detection

Required STAR Isolation

Long Range Full Duplex Networking

Advanced Countermeasures

Multifunctional Apertures

STAR Radar

140dB

100dB

170dB

150dB

160dB

120dB

130dB

110dB

Short Range Full Duplex Networking

Electronic Surveillance

during Transmit

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BGS - 814 November 2017

Prototype 8-element ALSTAR Array4 Receive Elements

RF Transceiver Chassis

Linear Patch Array

4 Transmit Elements Measured Isolation (100 MHz Waveform)

Transmitted waveform (EIRP*)

Signal and Noise Cancellation (Tx On)Thermal Noise Floor (Tx Off)

2.4 2.42 2.44 2.46 2.48 2.5Freq (GHz)

-120

-100

-80

-60

-40

-20

0

20

40

60

Pow

er( d

Bm

)

+44.3 dBm EIRP*

*EIRP: Effective Isotropic Radiated Power

Measured isolation of 140 dB over 100 MHz

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BGS - 914 November 2017

• MIT Lincoln Laboratory performs long term advanced technology development to support future DoD needs

• Advanced laser, imager and RF technologies have potential to impact future Army Aviation capabilities– Panelized lasers for lightweight directed energy weapons, optical communications and sensing– Germanium imagers for improved night vision with very large formats and mature

manufacturing infrastructure– Aperture-level STAR for advanced communication and countermeasure capabilities

Summary

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