{"id":3116,"date":"2026-08-01T12:01:42","date_gmt":"2026-08-01T04:01:42","guid":{"rendered":"http:\/\/www.rsmdailynews.com\/blog\/?p=3116"},"modified":"2026-08-01T12:01:42","modified_gmt":"2026-08-01T04:01:42","slug":"what-is-the-output-beam-profile-of-940nm-vcsel-4cac-6c2f3a","status":"publish","type":"post","link":"http:\/\/www.rsmdailynews.com\/blog\/2026\/08\/01\/what-is-the-output-beam-profile-of-940nm-vcsel-4cac-6c2f3a\/","title":{"rendered":"What is the output beam profile of 940nm VCSEL?"},"content":{"rendered":"

Hey there! As a supplier of 940nm VCSELs (Vertical-Cavity Surface-Emitting Lasers), I often get asked about the output beam profile of these little powerhouses. So, I thought I’d take a moment to break it down for you in a way that’s easy to understand. 940nm VCSEL<\/a><\/p>\n

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First off, let’s talk about what a 940nm VCSEL is. It’s a type of laser diode that emits light at a wavelength of 940 nanometers. This wavelength is in the near-infrared range, which means it’s not visible to the human eye but can be detected by certain sensors. VCSELs have become increasingly popular in recent years, especially in applications like facial recognition, proximity sensing, and LiDAR (Light Detection and Ranging) systems.<\/p>\n

Now, onto the output beam profile. The beam profile of a laser refers to the way the light is distributed across the cross-section of the beam. It’s an important characteristic because it can affect how the laser performs in different applications. There are a few different types of beam profiles that you might encounter with 940nm VCSELs, and I’ll go over the main ones here.<\/p>\n

Gaussian Beam Profile<\/h3>\n

The most common beam profile for 940nm VCSELs is the Gaussian beam profile. In a Gaussian beam, the intensity of the light is highest at the center of the beam and decreases gradually as you move away from the center in a bell-shaped curve. This type of beam profile is ideal for many applications because it provides a well-defined, concentrated beam of light.<\/p>\n

The Gaussian beam profile has a few key parameters that describe its shape. The beam waist is the smallest point in the beam, where the diameter is at its minimum. The divergence angle is the angle at which the beam spreads out as it travels away from the beam waist. These parameters are important because they can affect how the laser is focused and how far the beam can travel.<\/p>\n

One of the advantages of a Gaussian beam profile is that it can be easily focused using a lens. This makes it suitable for applications where you need to direct the laser light onto a specific target, such as in a LiDAR system. Another advantage is that the Gaussian beam profile is relatively stable, which means that the beam characteristics don’t change much over time or with small variations in the operating conditions.<\/p>\n

Top-Hat Beam Profile<\/h3>\n

Another type of beam profile that you might come across is the top-hat beam profile. In a top-hat beam, the intensity of the light is relatively uniform across the entire cross-section of the beam, with sharp edges. This type of beam profile is often used in applications where you need a more evenly distributed light source, such as in some illumination or projection applications.<\/p>\n

Creating a top-hat beam profile from a 940nm VCSEL can be a bit more challenging than achieving a Gaussian beam profile. One common method is to use beam shaping optics, such as diffusers or homogenizers, to convert the Gaussian beam into a top-hat beam. These optics work by spreading out the light and redistributing it to create a more uniform intensity distribution.<\/p>\n

The advantage of a top-hat beam profile is that it provides a more consistent illumination across the target area. This can be important in applications where you need to ensure that all parts of the target are exposed to the same amount of light, such as in some imaging or inspection systems.<\/p>\n

Modes and Beam Quality<\/h3>\n

In addition to the overall beam profile, the output of a 940nm VCSEL can also be affected by the laser’s modes. A mode is a specific pattern of light within the laser cavity. The most common modes in VCSELs are the fundamental mode and the higher-order modes.<\/p>\n

The fundamental mode is the lowest-energy mode of the laser, and it typically produces a Gaussian beam profile. Higher-order modes, on the other hand, can have more complex beam profiles and can cause the beam to be less well-behaved. In general, you want to operate the VCSEL in the fundamental mode to get the best beam quality.<\/p>\n

Beam quality is an important measure of how well the laser beam can be focused and how well it maintains its shape as it travels. It’s usually quantified using a parameter called the M\u00b2 factor. A lower M\u00b2 factor indicates better beam quality, with an M\u00b2 of 1 representing a perfect Gaussian beam. For most applications, you want an M\u00b2 factor as close to 1 as possible.<\/p>\n

Factors Affecting the Beam Profile<\/h3>\n

There are several factors that can affect the output beam profile of a 940nm VCSEL. One of the most important factors is the design of the laser itself. The structure of the VCSEL cavity, including the thickness and composition of the layers, can have a significant impact on the beam characteristics.<\/p>\n

The operating conditions of the VCSEL can also affect the beam profile. For example, the temperature of the laser can cause the refractive index of the materials to change, which can in turn affect the beam shape and divergence. The drive current is another important factor. Increasing the drive current can cause the laser to operate in higher-order modes, which can degrade the beam quality.<\/p>\n

Other factors that can affect the beam profile include the quality of the semiconductor materials used to make the VCSEL, the presence of any defects in the laser structure, and the way the laser is packaged. For example, if the VCSEL is not packaged properly, it can be subject to mechanical stress, which can distort the beam.<\/p>\n

Applications and the Beam Profile<\/h3>\n

The choice of beam profile depends on the specific application. As I mentioned earlier, a Gaussian beam profile is often preferred for applications like LiDAR and facial recognition because it can be easily focused and provides a well-defined beam. These applications require a high degree of accuracy and precision, and a Gaussian beam can help to achieve that.<\/p>\n

On the other hand, a top-hat beam profile is more suitable for applications where you need a more uniform illumination, such as in some industrial inspection or projection systems. In these applications, the goal is to provide a consistent amount of light across the entire target area, and a top-hat beam can do that more effectively.<\/p>\n

Why Choose Our 940nm VCSELs?<\/h3>\n

We’ve spent a lot of time and effort perfecting the output beam profile of our 940nm VCSELs. Our team of experts has developed advanced manufacturing techniques and optimization processes to ensure that our lasers produce high-quality beams with the desired characteristics.<\/p>\n

Whether you need a Gaussian beam for a high-precision LiDAR system or a top-hat beam for an industrial illumination application, we can provide you with the right VCSEL. We also offer custom solutions to meet your specific requirements. If you have a unique application that requires a specific beam profile or other characteristics, we can work with you to develop a tailored solution.<\/p>\n

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Our VCSELs are known for their reliability and performance. We use high-quality materials and rigorous testing procedures to ensure that each laser meets our strict standards. We also offer excellent customer support, so if you have any questions or need help with your application, our team is here to assist you.<\/p>\n

Let’s Talk!<\/h3>\n

808nm Diode Laser Bar<\/a> If you’re in the market for 940nm VCSELs and want to learn more about our products, I’d love to hear from you. Whether you’re a large corporation or a small startup, we’re committed to providing you with the best possible solutions for your needs. Feel free to reach out to us to discuss your requirements, and we can start the conversation about how our 940nm VCSELs can benefit your applications.<\/p>\n

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