SWIR Cameras and Imaging Applications

SWIR Cameras and Imaging Applications

Characterize Time

Takes less than 30 minutes

Compatibility

With Low (LM) & High (HM) lenses

Compatibility

With Low (LM) & High (HM) lenses

Performances

Fluorescent-based imaging systems

Performances

Fluorescent-based imaging systems

Characterize Time

Takes less than 30 minutes

Category:

WHAT IS SWIR?

SWIR is the acronym for Short Wave Infra-Red and refers to non-visible light falling roughly between 1400 and 3000 nanometers (nm) in wavelength.The visible spectrum ranges from 400nm to 700nm, therefore SWIR light is invisible to the human eye. In order to detect SWIR wavelengths, we need dedicated sensors made of InGaAs (Indium Gallium Arsenide) or MCT (mercury cadmium telluride) as silicon detectors are no longer sensitive to wavelengths larger than 1100 nm. SWIR cameras use InGaAs or MCT sensors. InGaAs sensors are the primary sensors used in typical SWIR range. MCT is also an option and can extend the SWIR range, but these sensors are usually more costly and application dependent. 

SWIR light interacts with objects similarly to visible light as it is reflective, consequently it exhibits shadows and contrasts in its imagery. Images from a SWIR camera are comparable to visible images in terms of resolution and detail. 

Objects that are almost the same color while imaging in visible region can be easily differentiated using SWIR light, making objects easily recognizable. This is one tactical advantage of imaging in SWIR compared to visible region. Some of the natural emitters of SWIR are ambient star light and background radiance, therefore SWIR is an excellent application for outdoor imaging. Conventional quartz/halogen bulbs also act as a SWIR light source. Depending on the application, some sensors in SWIR cameras can be adjusted to have linear or logarithmic response to avoid saturation.

Advantages of SWIR Cameras

There are many advantages of using SWIR over a conventional sensor. Some applications that are not possible to image in visible range can be imaged using SWIR range. One example, is silicon wafer inspection, which is only possible due to silicon being  transparent in the SWIR range. Other examples of materials that are transparent in SWIR region are; Sodium Chloride (NaCl) and Quartz (SiO2). Water vapor is also transparent in SWIR, making SWIR cameras more desirable when imaging through haze or fog. Applications where using SWIR is crucial are detailed in the following section.

Applications

SWIR imaging is used for a variety of applications in different aspects of the industry and research. These applications range from inspection, quality control, identification, detection, surveillance, and more. Here we summarize many applications where SWIR range is widely used. More applications are being discovered all the time.

Active/Range Imaging  for Security and Defense

SWIR is considered one of the most versatile technologies for the defense & security sectors. SWIR cameras can provide valuable information such as the ability to identify or recognize a target compared to MWIR & LWIR band cameras. It also brings better vision through harsh weather conditions such as fog or smoke. With a low readout noise and a high dynamic range, SWIR cameras can cope with the challenging requirements of the defense and security industry.

Gated imaging provides the ability to image a specific depth of a scene (i.e 3D imaging). There are multiple applications for gated imaging, including;  observation through severe weather conditions or other obscurants, estimation of distance and localization of obstacles (i.e. drone detection) with background suppression, and others.  Imaging devices must be fast enough to cope with reflected light from a laser source. SWIR cameras offer precision with the shortest effective exposure time, the shortest rise time, and highest dynamic range on the market. For this reason, these cameras can cover a broad number of situations in the field.

WiDy SenS Gated

 

Semiconductor/Solar Cell inspection

 A Silicon wafer is a thin substrate of semiconductor material and a key component for integrated circuits. An integrated circuit (IC) is a microscopic array of electronic circuits and components that has been implanted onto the surface of a single crystal of semiconductor material. Silicon wafers are formed from highly pure, nearly defect-free, monocrystalline silicon, thinly sliced from a silicon boule and serve as the substrate for microelectronic devices built in and over the wafer. The wafer undergoes many microfabrication process steps such as masking, etching, doping, and metallization.

They accumulate residual stress during the growth, sawing, grinding, etching and polishing process. Cracks may be generated throughout the process, and if undetected, the wafers that survive can be rendered unusable in subsequent manufacturing stages. Cracks may also happen when the the master integrated circuits are cut into individual IC. Therefore, inspecting the raw material substrate for impurities before processing and detecting defects during processing is critical to keep the costs down. SWIR cameras have a lot to offer on this aspect of production.

Silicon has the property to be transparent to infrared light. As a result, Indium gallium arsenide (InGaAs) cameras, operating in the SWIR wavelength band from 900 nm to 1700 nm, allow users to see through semiconductor silicon substrates. That offers a great benefit to the manufacturing process because infrared images highlight defects such as cracks inside the silicon wafer. Thus SWIR save manufacturers money and helps to eliminate waste. High frame rate SWIR cameras are extremely effective at these tasks

WiDy SenS, Goldeye SWIR InGaAs

Laser Welding/Laser Additive Manufacturing

Welding technology has been widely used for assembling metal parts in different industries. As it became more and more popular, a need for quality control has become paramount . Weld melt pool monitoring during or after welding is crucial for quality control purposes. It ensures consistency and reproducibility of the assembly. However, this monitoring is not very easy due to high temperatures, fast variation of light intensity and high level contrast differences. In this aspect, short wave infrared cameras bring valuable information to additive manufacturing processes. SWIR cameras are particularly well adapted for  all kinds of welding types (Tig, Mig, Plasma or Laser) due to their spectral response in SWIR band (i.e 900-1700 nm), as well as their high dynamic range 

SWIR cameras with InGaAs sensors work in a reflective imaging mode (i.e. same principle as imaging in visible spectrum) and at the same time in detection mode of infrared radiation emitted by hot objects (>250°C). Both weld pool and solidified melt (~1200nm) can be clearly seen while plasma and metal vapor (~600nm) are not. This brings an advantage as it overcomes the obstacles that occur if imaging is done in visible spectrum. The ability of SWIR cameras to see through smoke and high bandpass filter allows users to image the numerous details of the weld bead in real time. Furthermore, it allows assessing the size and shape, and the ability to control the heat profile of the weld bead. 

Advanced SWIR cameras can provide high-quality images of the melt-pool without any saturation and without disturbing circle of light.  All the relevant parameters can be monitored without any image processing.

 WiDy SWIR, WiDy SenS

Laser Beam Profiling

Lasers are used in many applications including; welding and cutting of materials, laser printing, fiber optics, medical applications, spectroscopy, surveying, and others. Due to extensive usage lasers loose their efficiency and it is crucial to assess the health of the laser. Laser profilers can identify the spatial characteristics to measure the quality and propagation of the laser beam. Additionally they provide accurate real-time measurements and allow users to measure the following characteristics:

  • Beam profile or 2D powerdistribution. The 2D intensity plot of a beam with the typical desired result being either a Gaussian or flat-top profile.
  • 2D beam size measurements
  • Beam divergence: measurement of the beam’s spread with distance
  • Beam quality with M2: the focusing ability of the laser
  • Pointing stability

Short wave infrared (SWIR) lasers cover the wavelengths ranging from 900 nm to 1700 nm, and are invisible to the human eye making real time assessment more favorable. SWIR beam profilers are necessary to assess the quality of the beam in shortwave infrared spectrum. Laser Beam profilers for SWIR lasers use InGaAs (indium gallium arsenide) or MCT or HgCdTe (mercury cadmium telluride) detectors. These sensors are sensitive to different wavelength ranges. The most commonly used sensor technology for beam profiling in the SWIR spectrum is InGaAs because it does not necessitate cryogenic cooling (using liquid nitrogen or a small stirling cycle refrigerator unit), which makes it more practical and affordable than MCT.

CinCam InGaAs/Goldeye SWIR, CinSquare InGaAs (M2 measurements)

Small Animal Imaging 

Small animal imaging is one of the main research areas for preclinical studies, including but not limited to; drug discovery, drug effectiveness, and early detection of cancer. Over time, imaging in the SWIR range became more profitable for scientists studying small animals. The short wave infrared (SWIR) range has several advantages compared to visible and infrared wavelengths in the domain of in vivo imaging. SWIR light provides higher depth of penetration while maintaining high resolution, low light absorption and reduced scattering within the tissue. This makes SWIR light desirable to study living organisms.

One of the biggest advantages of the SWIR range is that the autofluorescence is negligible. This low level autofluorescence increases the contrast and sensitivity compared to conventional imaging in NIR and visible ranges. Some of NIR fluorescence imaging contrast agents such as; ICG (indocyanine green), IRDye800CW and IR-12N3, has a non-negligible long tails passing 1500 nm region (NIR-II/SWIR) [1]. InGaAs (indium gallium arsenide) based SWIR cameras fill the gap for imaging in NIR-II/SWIR wavelength range (900-1700nm) where silicon detectors are no longer sensitive.

 C-RED2

Astronomy

Short Wave Infrared (SWIR) cameras are used in astronomy research to study the J-, H- and K- bands. They offer high-resolution, and are cooled which makes them ideal for telescopes. Integration times can be as long as 3 minutes with low readout noise when cooled to -60°C. Adaptive optics are widely used in astronomy research because the atmospheric turbulence causes spatial and temporal wavefront distortions. This is a highly limiting factor for capturing high resolution images of astronomical phenomena. A fast and sensitive camera is required for these applications.SWIR cameras can have high frame rate while maintaining low noise levels. This makes them desirable for astronomy studies requiring adaptive optics.

C-RED1, CRED-2, C-RED2-ER

 

Carbon Nanotubes Imaging 

SWIR cameras can be used for detection of single-walled carbon nanotubes requiring fast frame rates. Single-walled carbon nanotubes (SWCNT) have been established as remarkable fluorophores for probing the nanoscale organization of biological tissues [1,2]. They are stiff, quasi-one-dimensional nanostructures, with a small diameter (~1nm) which enables excellent penetration into complex environments, and a large length (100nm to 1µm) which slows down their diffusion and thus allows the tracking of single fluorescent particles. Finally, their bright and stable near-infrared (NIR) fluorescence allows long-term tracking deep in biological tissues without suffering from biological autofluorescence.

SWCNTs could be detected in distant regions of the brain extracellular space (ECS) following their injection into the lateral ventricles of young rat brains, and the tracking of their diffusion. This yields novel and quantitative insights about the local morphology and viscosity variations within the brain ECS[1,2]. Such studies require a camera capable of tracking single-walled carbon nanotubes at high speed, making SWIR cameras desirable. One limiting factor for the spatial resolution of such diffusion analyses is the ability to observe displacements of SWCNTs over short time lags. 

CRED-2

Description

WHAT IS SWIR?

SWIR is the acronym for Short Wave Infra-Red and refers to non-visible light falling roughly between 1400 and 3000 nanometers (nm) in wavelength.The visible spectrum ranges from 400nm to 700nm, therefore SWIR light is invisible to the human eye. In order to detect SWIR wavelengths, we need dedicated sensors made of InGaAs (Indium Gallium Arsenide) or MCT (mercury cadmium telluride) as silicon detectors are no longer sensitive to wavelengths larger than 1100 nm. SWIR cameras use InGaAs or MCT sensors. InGaAs sensors are the primary sensors used in typical SWIR range. MCT is also an option and can extend the SWIR range, but these sensors are usually more costly and application dependent. 

SWIR light interacts with objects similarly to visible light as it is reflective, consequently it exhibits shadows and contrasts in its imagery. Images from a SWIR camera are comparable to visible images in terms of resolution and detail. 

Objects that are almost the same color while imaging in visible region can be easily differentiated using SWIR light, making objects easily recognizable. This is one tactical advantage of imaging in SWIR compared to visible region. Some of the natural emitters of SWIR are ambient star light and background radiance, therefore SWIR is an excellent application for outdoor imaging. Conventional quartz/halogen bulbs also act as a SWIR light source. Depending on the application, some sensors in SWIR cameras can be adjusted to have linear or logarithmic response to avoid saturation.

Advantages of SWIR Cameras

There are many advantages of using SWIR over a conventional sensor. Some applications that are not possible to image in visible range can be imaged using SWIR range. One example, is silicon wafer inspection, which is only possible due to silicon being  transparent in the SWIR range. Other examples of materials that are transparent in SWIR region are; Sodium Chloride (NaCl) and Quartz (SiO2). Water vapor is also transparent in SWIR, making SWIR cameras more desirable when imaging through haze or fog. Applications where using SWIR is crucial are detailed in the following section.

Applications

SWIR imaging is used for a variety of applications in different aspects of the industry and research. These applications range from inspection, quality control, identification, detection, surveillance, and more. Here we summarize many applications where SWIR range is widely used. More applications are being discovered all the time.

Active/Range Imaging  for Security and Defense

SWIR is considered one of the most versatile technologies for the defense & security sectors. SWIR cameras can provide valuable information such as the ability to identify or recognize a target compared to MWIR & LWIR band cameras. It also brings better vision through harsh weather conditions such as fog or smoke. With a low readout noise and a high dynamic range, SWIR cameras can cope with the challenging requirements of the defense and security industry.

Gated imaging provides the ability to image a specific depth of a scene (i.e 3D imaging). There are multiple applications for gated imaging, including;  observation through severe weather conditions or other obscurants, estimation of distance and localization of obstacles (i.e. drone detection) with background suppression, and others.  Imaging devices must be fast enough to cope with reflected light from a laser source. SWIR cameras offer precision with the shortest effective exposure time, the shortest rise time, and highest dynamic range on the market. For this reason, these cameras can cover a broad number of situations in the field.

WiDy SenS Gated

 

Semiconductor/Solar Cell inspection

 A Silicon wafer is a thin substrate of semiconductor material and a key component for integrated circuits. An integrated circuit (IC) is a microscopic array of electronic circuits and components that has been implanted onto the surface of a single crystal of semiconductor material. Silicon wafers are formed from highly pure, nearly defect-free, monocrystalline silicon, thinly sliced from a silicon boule and serve as the substrate for microelectronic devices built in and over the wafer. The wafer undergoes many microfabrication process steps such as masking, etching, doping, and metallization.

They accumulate residual stress during the growth, sawing, grinding, etching and polishing process. Cracks may be generated throughout the process, and if undetected, the wafers that survive can be rendered unusable in subsequent manufacturing stages. Cracks may also happen when the the master integrated circuits are cut into individual IC. Therefore, inspecting the raw material substrate for impurities before processing and detecting defects during processing is critical to keep the costs down. SWIR cameras have a lot to offer on this aspect of production.

Silicon has the property to be transparent to infrared light. As a result, Indium gallium arsenide (InGaAs) cameras, operating in the SWIR wavelength band from 900 nm to 1700 nm, allow users to see through semiconductor silicon substrates. That offers a great benefit to the manufacturing process because infrared images highlight defects such as cracks inside the silicon wafer. Thus SWIR save manufacturers money and helps to eliminate waste. High frame rate SWIR cameras are extremely effective at these tasks

WiDy SenS, Goldeye SWIR InGaAs

Laser Welding/Laser Additive Manufacturing

Welding technology has been widely used for assembling metal parts in different industries. As it became more and more popular, a need for quality control has become paramount . Weld melt pool monitoring during or after welding is crucial for quality control purposes. It ensures consistency and reproducibility of the assembly. However, this monitoring is not very easy due to high temperatures, fast variation of light intensity and high level contrast differences. In this aspect, short wave infrared cameras bring valuable information to additive manufacturing processes. SWIR cameras are particularly well adapted for  all kinds of welding types (Tig, Mig, Plasma or Laser) due to their spectral response in SWIR band (i.e 900-1700 nm), as well as their high dynamic range 

SWIR cameras with InGaAs sensors work in a reflective imaging mode (i.e. same principle as imaging in visible spectrum) and at the same time in detection mode of infrared radiation emitted by hot objects (>250°C). Both weld pool and solidified melt (~1200nm) can be clearly seen while plasma and metal vapor (~600nm) are not. This brings an advantage as it overcomes the obstacles that occur if imaging is done in visible spectrum. The ability of SWIR cameras to see through smoke and high bandpass filter allows users to image the numerous details of the weld bead in real time. Furthermore, it allows assessing the size and shape, and the ability to control the heat profile of the weld bead. 

Advanced SWIR cameras can provide high-quality images of the melt-pool without any saturation and without disturbing circle of light.  All the relevant parameters can be monitored without any image processing.

 WiDy SWIR, WiDy SenS

Laser Beam Profiling

Lasers are used in many applications including; welding and cutting of materials, laser printing, fiber optics, medical applications, spectroscopy, surveying, and others. Due to extensive usage lasers loose their efficiency and it is crucial to assess the health of the laser. Laser profilers can identify the spatial characteristics to measure the quality and propagation of the laser beam. Additionally they provide accurate real-time measurements and allow users to measure the following characteristics:

  • Beam profile or 2D powerdistribution. The 2D intensity plot of a beam with the typical desired result being either a Gaussian or flat-top profile.
  • 2D beam size measurements
  • Beam divergence: measurement of the beam’s spread with distance
  • Beam quality with M2: the focusing ability of the laser
  • Pointing stability

Short wave infrared (SWIR) lasers cover the wavelengths ranging from 900 nm to 1700 nm, and are invisible to the human eye making real time assessment more favorable. SWIR beam profilers are necessary to assess the quality of the beam in shortwave infrared spectrum. Laser Beam profilers for SWIR lasers use InGaAs (indium gallium arsenide) or MCT or HgCdTe (mercury cadmium telluride) detectors. These sensors are sensitive to different wavelength ranges. The most commonly used sensor technology for beam profiling in the SWIR spectrum is InGaAs because it does not necessitate cryogenic cooling (using liquid nitrogen or a small stirling cycle refrigerator unit), which makes it more practical and affordable than MCT.

CinCam InGaAs/Goldeye SWIR, CinSquare InGaAs (M2 measurements)

Small Animal Imaging 

Small animal imaging is one of the main research areas for preclinical studies, including but not limited to; drug discovery, drug effectiveness, and early detection of cancer. Over time, imaging in the SWIR range became more profitable for scientists studying small animals. The short wave infrared (SWIR) range has several advantages compared to visible and infrared wavelengths in the domain of in vivo imaging. SWIR light provides higher depth of penetration while maintaining high resolution, low light absorption and reduced scattering within the tissue. This makes SWIR light desirable to study living organisms.

One of the biggest advantages of the SWIR range is that the autofluorescence is negligible. This low level autofluorescence increases the contrast and sensitivity compared to conventional imaging in NIR and visible ranges. Some of NIR fluorescence imaging contrast agents such as; ICG (indocyanine green), IRDye800CW and IR-12N3, has a non-negligible long tails passing 1500 nm region (NIR-II/SWIR) [1]. InGaAs (indium gallium arsenide) based SWIR cameras fill the gap for imaging in NIR-II/SWIR wavelength range (900-1700nm) where silicon detectors are no longer sensitive.

 C-RED2

Astronomy

Short Wave Infrared (SWIR) cameras are used in astronomy research to study the J-, H- and K- bands. They offer high-resolution, and are cooled which makes them ideal for telescopes. Integration times can be as long as 3 minutes with low readout noise when cooled to -60°C. Adaptive optics are widely used in astronomy research because the atmospheric turbulence causes spatial and temporal wavefront distortions. This is a highly limiting factor for capturing high resolution images of astronomical phenomena. A fast and sensitive camera is required for these applications.SWIR cameras can have high frame rate while maintaining low noise levels. This makes them desirable for astronomy studies requiring adaptive optics.

C-RED1, CRED-2, C-RED2-ER

 

Carbon Nanotubes Imaging 

SWIR cameras can be used for detection of single-walled carbon nanotubes requiring fast frame rates. Single-walled carbon nanotubes (SWCNT) have been established as remarkable fluorophores for probing the nanoscale organization of biological tissues [1,2]. They are stiff, quasi-one-dimensional nanostructures, with a small diameter (~1nm) which enables excellent penetration into complex environments, and a large length (100nm to 1µm) which slows down their diffusion and thus allows the tracking of single fluorescent particles. Finally, their bright and stable near-infrared (NIR) fluorescence allows long-term tracking deep in biological tissues without suffering from biological autofluorescence.

SWCNTs could be detected in distant regions of the brain extracellular space (ECS) following their injection into the lateral ventricles of young rat brains, and the tracking of their diffusion. This yields novel and quantitative insights about the local morphology and viscosity variations within the brain ECS[1,2]. Such studies require a camera capable of tracking single-walled carbon nanotubes at high speed, making SWIR cameras desirable. One limiting factor for the spatial resolution of such diffusion analyses is the ability to observe displacements of SWCNTs over short time lags. 

CRED-2