Utilizing SWIR-based Camera Platforms for Laser Beam Profiling
Camera-based systems are the norm for pulsed laser beam profiling. The cameras used are designed to measure and monitor the beam’s length. The applications of these systems are many and varied. Find out the benefits of cameras with SWIR for laser beam profiling.
Benefits of Silicon-based Optical Systems
Silicon-based charge-coupled devices and silicon-based complementary metal-oxide-semiconductors (e.g. CCDs and CMOS) are commonly used in high-performance imaging and are able to detect wavelengths that range from soft x-rays into near-infrared (NIR). In general the quantum efficiency of CCDs diminishes rapidly as the detection wavelength expands higher into that NIR range. In wavelengths that exceed 1100 nm, using conventional CCDs and CMOS system light cannot be absorbed by a silicon crystal because the photons that are in this kind of light do not have sufficient energy to cause the electron to jump.
The latter model has large area sensors with excellent resolution. This is essential for precise measurements of both small and large laser beams. Both types of profilers count the wavelengths that range from UV through near-infrared (IR).
SWIR Vision Systems has a proprietary camera line for laser beam profiling with an 800 to 1,700 nm sensor band range based upon colloidal quantum dots (CQD) – thin film photodiodes that are made entirely made from readout quartz wafers. They are able to accomplish in SWIR imaging what CMOS image sensors, as well as micro-bolometer arrays, accomplished for visible and longwave imaging and visible infrared imaging, respectively. CQD laser imaging sensors from SWIR are available in both camera-based and camera-less models.
Prior to making a decision about the detector chosen for the application, one should be aware of every aspect of the application and how wavelengths react.
Selecting an optical system to perform applied pulsed laser beam measurement
Regarding the use of the technology, there isn’t a single-size-fits-all profiler available, since different lasers have different wavelengths. Additionally, the lasers are equipped with different beam dimensions and powers, so they require different optical systems. The optical systems should be equipped with wavelength-specific attenuators, as well as antireflective coatings to accurately measure the spectrum. These differences introduce errors into the measurement process.
Camera-based laser beam profiling systems are the most commonly used option when it comes to large-scale beam measurements. These systems employ a CMOS or photodiode-based photodetector to detect the wavelength. Camera-based systems can be used in many different ways that include industrial applications, in the field of research and development as well as for military purposes.
Camera-based systems that use pulsed laser beam profilers provide many advantages over slit-based devices. Slit-based systems allow the measurement of very small beams directly while camera-based systems detect both unfocused and concentrated beams. They are especially useful for factory-floor applications, where accuracy and repeatability are essential.
Camera-based systems that use pulsed laser beam profilers are incredibly sensitive to artifacts associated with narrow-linewidth laser radiation. These artifacts can be eliminated by meticulous optical design.
Camera-based systems are ideal for a variety of applications.The cameras that are used for pulsed laser beam profiling are usually C-mount compatible. The camera head itself has no faceplate that is in front of the chip in the sensor, so there’s no need to purchase a separate ND filter (the ND filters remove all light sources from on the chip).
Unlike conventional laser beam measurements that require an optical lens with a fixed aperture to see a beam, Acuros CDQ Sensors can laser beam profile with or without cameras. Cameras are not always suitable for large-beam applications since it’s not able to detect beams with smaller dimensions.
Applications
The applications of SWIR Laser Profiling are incredibly diverse. These measurements are beneficial in a myriad of ways such as laser collimation and characterisation. There are numerous advantages of making use of CCD beam profilers. CCD beam profiler, including the ability to measure astigmatism, as well as its ability to move around the beam’s path. For example an CCD beam profiler can determine the intensity of the laser beam which is crucial for determining for astigmatism when imaging medically. Moreover beam profilers using CCD can detect astigmatism with no cover glass. Furthermore, the lack of a cover glass is a key aspect of a CCD beam profiler. While a CCD camera might not be suitable for all applications however, it is generally preferred for SWIR laser beam monitoring, dependent on the task that is being used.