Skip to main content

Optical Properties of LED Array

An LED array consists of multiple light-emitting diodes (LEDs) arranged in a specific pattern or configuration to achieve uniform lighting, higher intensity, or specific illumination characteristics. These arrays are widely used in applications such as displays, lighting systems, optical communication, and sensing.

The optical properties of an LED array are critical for understanding how it interacts with light and how it can be used in applications such as illumination, displays, or sensing. These properties depend on the individual LEDs' characteristics and the array's geometry and configuration.

LEDs in an array emit specific wavelengths, depending on the semiconductor material used in these categories. Monochromatic, i.e. single color (e.g., red, green, blue); Full spectrum, i.e. arrays with RGB LEDs allow color tuning by mixing red, green, and blue light; White light, i.e. achieved using phosphor-coated LEDs or mixing RGB LEDs. The property of elements in the array can be an angular emission profile. Each LED emits light in a Lambertian pattern (wide-angle distribution), although some have built-in optics for narrower or more focused beams. Defined by the half-power angle, the light intensity drops to 50% of the peak at this angle. Typical beam divergence for LEDs is 30° to 120°, depending on the lens. The overall beam pattern depends on the LED arrangement and any external optics.

Definitions of Source Array at NSC Mode

An LED array can be modeled by the object type Source Diode in Non sequential mode. The source diode model can be used to define one diode, a 1D array of diodes, or a 2D array of diodes. In the Non-Sequential Component Editor, add a new object by inserting a row, as below.

The Source Diode object represents an LED or laser diode with an angular intensity profile defined by two divergence angles: θ (in the XZ plane) and ϕ (in the YZ plane). Layout Rays visually display the geometry and interaction of rays with the system components. These rays are a subset of all rays and are used for layout visualization rather than detailed analysis. Analysis Rays are used for detailed evaluation of ray behavior, such as intensity distribution, power, or efficiency. These are generated by running a ray trace, with all rays contributing to the analysis results.

Feature

Layout Rays

Analysis Rays

Purpose

Visual layout of ray paths

Detailed simulation for quantitative analysis

Ray Count

Limited

Large number

Scope

Visualization only

Contributes to system analysis results

Speed

Faster visualization

Slower due to computation requirements

 

X and Y divergence (αx and αy) in degrees are set differently as 6 and 12 degrees. X and Y supergaussian factor (Gx and Gy) are 1.0, then a typical Gaussian distribution results. Both Gx and Gy must be ≥ 0.01 and ≤ 50.0. Gx can be used to change the angular distribution of the Source Diode using a super ellipse function. Numbers of diodes in X/Y are both defined as 5. Delta X and Y are distance between elements.

X- and Y- widths (Wx and Wy) denote half width of the rectangular region from which the rays emanate in lens units. Here it is defined as zero as no distance is left. X- and Y- sigma Gaussian width (Sx and Sy) of the spatial distribution in both directions. Hx and Hy are 0.01 here, which defines spatial distribution super Gaussian factors. The relationship between the parameters is defined below. If Hx is 1.0, then a typical Gaussian distribution results. Both Hx and Hy must be ≥ 0.01.

Model Layout and Ray Tracing

With a 20 mm by 20 mm rectangular detector placed 12 mm away from the source array, the 3D model is shown as below:

After raytracing, the incoherent irradiance is below:

If the presence of data is changed to “Radiant Intensity”, it shows the power per solid angle in radians as a function of incident angle upon the detector.

Ozen Engineering Expertise

Ozen Engineering Inc. leverages its extensive consulting expertise in CFD, FEA, optics, photonics, and electromagnetic simulations to achieve exceptional results across various engineering projects, addressing complex challenges like multiphase flows, erosion modeling, and channel flows using Ansys software.

We offer support, mentoring, and consulting services to enhance the performance and reliability of your hydraulic systems. Trust our proven track record to accelerate projects, optimize performance, and deliver high-quality, cost-effective results for both new and existing water control systems. For more information, please visit https://ozeninc.com

Jeffery Huang
Post by Jeffery Huang
November 26, 2024