Utilizing SWIR-based Camera Platforms for Laser Beam Profiling

Systems based on cameras are considered to be the standard used for laser beam profiles using pulsed light. The cameras used are designed to measure and monitor the beam’s length. The applications of these systems are many and varied. Learn more about the advantages of using SWIR camera-based systems for laser beam profiling.

Advantages of Silicon-based Optical Systems

Silicon-based charge-coupled devices and silicon-based complementary metal-oxide-semiconductors (e.g. CCDs as well as CMOS) are often used in high-performance imaging and are capable of detecting wavelengths that extend from soft x-rays into the near infrared (NIR). In general, the quantum efficiency of CCDs decreases when the detection wavelength increases higher into the NIR range. At wavelengths in excess of 1100 nm, with traditional CCDs and CMOS system light cannot be taken up by a silicon crystal because the photons that are in this type of light lack enough energy to cause an electron to leap.

The latter has large-area sensors that have high resolution, which is essential for obtaining precise measurements of both small and massive laser beams. Both types of profilers measure wavelengths ranging 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 constructed entirely from quartz readout wafers. They could accomplish the same thing for SWIR imaging what CMOS sensors for images and micro-bolometer arrays, accomplished for visible and longwave imaging and visible infrared imaging, respectively. SWIR CQD laser imaging sensors are available in both camera-based as well as camera-less variants.

Before making a choice on the detector used to detect the object, it is important to take into consideration every aspect of the application, including how wavelengths respond.

Selecting an optical device for the measurement of laser beams with pulses

In terms of the application of this technology, there is no single-size-fits-all profiler available, since different lasers have different wavelengths. Additionally, the lasers are equipped with different beam dimensions and powers, which means it is necessary to use different optical equipment. The optical systems should include wavelength-specific attenuators as well as antireflective coatings in order to precisely detect the spectrum. These differences introduce errors into the measurement process.

Camera-based systems for profiling laser beams are the most commonly used option to measure large beams. These systems employ the CMOS or photodiode-based detector to detect the wavelength. In fact, camera-based systems are used in a variety of applications that include industrial settings, research and development, and within military use.

Camera-based systems for the pulsed beam profiler have several advantages over slit-based devices. Slit-based systems allow the measurement of beams with very small diameters directly while camera-based systems measure both concentrated and unfocused beams. They are particularly useful in factory floor applications, where accuracy and repeatability are essential.

Camera-based systems for pulsed laser beam profilers are extremely sensitive to the effects of low-linewidth laser beams. The artifacts are removed by careful optical design.

Camera-based systems are an excellent choice for many applications.The cameras used to perform Pulsed Laser beam Profiling (PLB) are generally C-mount compatible. The camera head has no faceplate in front of the sensor chip and there’s no requirement to buy a separate ND filter (the ND filters remove any light that is not directed towards the sensor chip).

In contrast to conventional laser beam measurements, which require a lens that has a fixed aperture to view a beam, Acuros CDQ Sensors can laser beam profile without a camera. A camera is not the best choice for large beam applications since it’s not able to take beams with smaller diameters.

Applications

The uses of SWIR Laser Profiling are extremely diverse. These measurements are useful in a myriad of ways that include laser collimation as well as characterization. There are many advantages to making use of a CCD beam profiler such as its ability to measure astigmatism and its ability to move along the beam path. For instance, a CCD beam profiler is able to measure the intensity of the laser beam that is essential for measuring astigmatism in medical imaging. Moreover the CCD beam profiler can detect astigmatism with no cover glass. Moreover, the absence of a cover glass is an important aspect of CCD beam profiler. Although a CCD camera might not be suitable for all purposes however, it is generally preferred to use for SWIR laser beam monitoring, according to the particular application that is being used.