The proliferation of man-portable air-defense systems (MANPADS) is extremely wide. MANPADS are responsible for over 60% of total aircraft casualties since 1960’s. It is estimated that over 500,000 of these systems are deployed worldwide with a large number being out of governmental control. Directional infrared countermeasure (DIRCM) systems have been deployed in order to counter the threat. Laser based DIRCM system requires laser sources which can operate in bands I, II and IV. Up to day bands II and IV are covered by compact and lightweight quantum cascade lasers (QCLs), but for wavelength generation in band I, bulky and expensive solid-state or fiber laser solutions are used. Recent development of GaSb laser diode technology at Brolis Semiconductors greatly improved optical output powers and efficiency of laser diodes working in 1900 - 2450 nm range (band I). In this work we present a laser diode module which is based on incoherent beam combining of two high-power GaSb laser diode emitters working in 2.1-2.3 μm spectral band. This laser module is capable of providing directional beam with radiant intensity value of more than 30 kW/str. Module is extremely compact and lightweight (<50 g). E-O efficiency of the module is 15% and it can be operated in CW or pulsed operation modes replicating any waveform required for DIRCM application.
Continuous advances in low-cost MANPAD heat-seeking missile technology over the past 50 years remains the number one hostile threat to airborne platforms globally responsible for over 60 % of casualties. Laser based directional countermeasure (DIRCM) technology have been deployed to counter the threat. Ideally, a laser based DIRCM system must involve a number of lasers emitting at different spectral bands mimicking the spectral signature of the airborne platform. Up to now, near and mid infrared spectral bands have been covered with semiconductor laser technology and only SWIR band remained with bulky fiber laser technology. Recent technology developments on direct-diode GaSb laser technology at Brolis Semiconductors offer a replacement for the fiber laser source leading to significant improvements by few orders of magnitude in weight, footprint, efficiency and cost. We demonstrate that with careful engineering, several multimode emitters can be combined to provide a directional laser beam with radiant intensity from 10 kW/sr to 60 kW/sr in an ultra-compact hermetic package with weight < 30 g and overall efficiency of 15 % in the 2.1- 2.3 micron spectral band offering 150 times improvement in efficiency and reduction in footprint. We will discuss present results, challenges and future developments for such next-generation integrated direct diode DIRCM modules for SWIR band.
Compact high-power 2100 nm laser diode module for next-generation directional infrared countermeasure (DIRCM) systems is presented. Next-generation DIRCM systems require compact, light-weight and robust laser modules which could provide intense IR light emission capable of disrupting the tracking sensor of heat-seeking missile. Currently used solid-state and fiber laser solutions for mid-IR band are bulky and heavy making them difficult to implement in smaller form-factor DIRCM systems. Recent development of GaSb laser diode technology greatly improved optical output powers and efficiencies of laser diodes working in 1900 - 2450 nm band [1] while also maintaining very attractive size, weight, power consumption and cost characteristics.
2100 nm laser diode module presented in this work performance is based on high-efficiency broad emitting area GaSb laser diode technology. Each laser diode emitter is able to provide 1 W of CW output optical power with working point efficiency up to 20% at temperature of 20 °C. For output beam collimation custom designed fast-axis collimator and slow-axis collimator lenses were used. These lenses were actively aligned and attached using UV epoxy curing. Total 2 emitters stacked vertically were used in 2100 nm laser diode module. Final optical output power of the module goes up to 2 W at temperature of 20 °C. Total dimensions of the laser diode module are 35 x 25 x 16 mm (L x W x H) with a weight of ~28 grams. Finally output beam is bore-sighted to mechanical axes of the module housing allowing for easy integration into next-generation DIRCM systems.
In this work we present latest achievements on gain chips as sources for single-frequency tunable laser absorption spectroscopy and sensing. External cavity lasers based on Brolis Semiconductors (2.05 – 2.45) μm wavelengths GaSb gain chips exhibited single mode laser emission with linewidths <100 kHz and output powers of <5 mW in the entire tuning range of <100 nm per chip. Continuous current tuning of 60 GHz and mode-hop free piezo tuning of 26 GHz were demonstrated. Additionally, we report on extended wavelengths range by demonstrating low spectral modulation 850 nm GaAs-based gain chips. Finally, experimental results on GaSb-based gain chip integration with silicon photonics are presented.
One of the most important factor of success in battlefield is the ability to remain undetected by the opposing forces while also having an ability to detect all possible threats. Illumination and pointing systems working in NIR and SWIR bands are presented. Wavelengths up to 1100 nm can be registered by newest generation image intensifier tubes, CCD and EMCCD sensors. Image intensifier tubes of generation III or older are only limited up to wavelength of ~900 nm [1]. Longer wavelengths of 1550 nm and 1625 nm are designed to be used with SWIR electro-optical systems and they cannot be detected by any standard night vision system. Long range SWIR illuminators and pointers have beam divergences down to 1 mrad and optical powers up to 1.5 W. Due to lower atmospheric scattering SWIR illuminators and pointers can be used at extremely long distances up to 10s of km and even further during heavy weather conditions. Longer wavelengths of 2100 nm and 2450 nm are also presented, this spectrum band is of great interest for direct infrared countermeasure (DIRCM) applications.
State-of-the-art SWIR and LWIR electro-optical systems are presented. Sensitive InGaAs sensors coupled with “fast" (low F/#) optical lenses can provide complete night vision, detection of all NIR and SWIR laser lines, penetration through smoke, dust and fog. Finally beyond-state-of-the-art uncooled micro-bolometer LWIR systems are presented featuring ultra-high sensor sensitivities of 20 mK.
In this work we present latest results on mid-infrared GaSb gain chips as high-output power narrow-linewidth continuouswave single-frequency laser sources for ultra-widely tunable spectroscopy and sensing applications. More than 30 mW CW output power with over 100 nm / chip tuning and < 1 MHz linewidth performance is demonstrated in the entire band from 1900 nm – 2450 nm covering most essential absorption features from CO, CO2, NH3, CH4 and N2O for environmental and medical applications. Finally, we report on complete single-frequency laser system with integrated gain-chip for highresolution spectroscopy and sensor applications.
Mid-infrared spectral region (2-4 μm) is gaining significant attention recently due to the presence of
numerous enabling applications in the field of gas sensing, medical, and defense applications. Gas sensing in this spectral
region is attractive due to the presence of numerous absorption lines for such gases as methane, ethane, ozone, carbon
dioxide, carbon monoxide, etc. Sensing of the mentioned gas species is of particular importance for applications such as
atmospheric LIDAR, petrochemical industry, greenhouse gas monitoring, etc. Defense applications benefit from the
presence of covert atmospheric transmission window in the 2.1-2.3 micron band which is more eye-safe and offers less
Rayleigh scattering than the conventional atmospheric windows in the near-infrared. Major requirement to enable these
application is the availability of high-performance, continuous-wave laser sources in this window. Type-I GaSb-based
laser diodes are ideal candidates for these applications as they offer direct emission possibility, high-gain and continuous
wave operation. Moreover, due to the nature of type-I transition, these devices have a characteristic low operation
voltage, which results in very low input powers and high wall-plug efficiency.
In this work, we present recent results of 2 μm – 3.0 μm wavelength room-temperature CW light sources based
on type-I GaSb developed at Brolis Semiconductors. We discuss performance of defense oriented high-power multimode
laser diodes with < 1 W CW power output with over 30 % WPE as well as ~ 100 mW single TE00 Fabry-Perot chips. In
addition, recent development efforts on sensing oriented broad gain superluminescent gain chips will be presented.
Mid-infrared spectral region (2-4 μm) is gaining significant attention recently due to the presence of numerous enabling applications in the field of gas sensing, medical, environmental and defense applications. Major requirement for these applications is the availability of laser sources in the atmospheric transmission window free of water vapor absorption, such as the 2-2.3 μm spectral window. Type-I GaSb-based laser diodes are ideal candidates for these applications being compact, electrically pumped, power efficient and able to operate at room temperature in continuous-wave. Moreover, due to the nature of type-I transition these devices have characteristic low operation voltage, typically below 1 V, resulting in low power consumption, and high-temperature of operation. In this work, we present recent progress of 2.1 μm wavelength single-spatial mode GaSb type-I laser diode development at Brolis Semiconductors. Experimental device structures were grown by solid-source multi-wafer MBE, consisting of an active region with 2 compressively strained (~1.3 %) GaInAsSb quantum wells. Epi-wafers were processed into a ridge-waveguide devices and mounted on Cu or CuW heatsink. Presented devices feature state-of-the art performance in CW mode with < 1.2 W and 30 % WPE for single emitter device as well as 9 W and 28 % WPE for a laser diode bar.
Mid-infrared spectral region (2-4 μm) is gaining significant attention recently due to the presence of numerous enabling applications in the field of gas sensing, medical, environmental and defense applications. Major requirement for these applications is the availability of laser sources in this spectral window. Type-I GaSb-based laser diodes are ideal candidates for these applications being compact, electrically pumped, power efficient and able to operate at room temperature in continuous-wave. Moreover, due to the nature of type-I transition; these devices have a characteristic low operation voltage, typically below 1 V, resulting in low power consumption, and high-temperature of operation. In this work, we present recent progress of 2.7 μm – 3.0 μm wavelength single-spatial mode GaSb type-I laser diode development at Brolis Semiconductors. Experimental device structures were grown by solid-source multi-wafer MBE, consisting of an active region with 2 compressively strained (~1.3 %-1.5 %) GaInAsSb quantum wells with GaSb barriers for 2.7 μm devices and quinternary AlGaInAsSb barriers for 3.0 μm devices. Epi-wafers were processed into a narrow-ridge (2-4 μm) devices and mounted p-side up on CuW heatsink. Devices exhibited very low CW threshold powers of < 100 mW, and single spatial mode (TE00) operation with room-temperature output powers up to 40 mW in CW mode. Operating voltage was as low as 1.2 V at 1.2 A. As-cleaved devices worked CW up to 50 deg C.
Mid-infrared spectral region (2-4 μm) is gaining significant attention recently due to the presence of
numerous enabling applications in the field of gas sensing, medical, environmental and defense applications. Major
requirement for these applications is the availability of laser sources in this spectral window. Type-I GaSb-based laser
diodes are ideal candidates for these applications being compact, electrically pumped, power efficient and able to operate
at room temperature in continuous-wave. Moreover, due to the nature of type-I transition these devices have
characteristic low operation voltage, typically below 1 V, resulting in low power consumption, and high-temperature of
operation.
In this work, we present recent progress of 2.1 μm wavelength single-spatial mode GaSb type-I laser diode
development at Brolis Semiconductors. Experimental device structures were grown by solid-source multi-wafer MBE,
consisting of an active region with 2 compressively strained (~1.3 %) GaInAsSb quantum wells. Epi-wafers were
processed into a narrow-ridge (3-5 μm) devices and mounted p-side up on CuW heatsink. Devices exhibited very low
CW threshold powers of < 30 mW, and single spatial mode (TE00) operation with room-temperature output powers up
to 200 mW in CW mode with a far-field fast axis divergence angle of ~ 57 degrees.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.