Simulation of light and energy absorption is critically important in many optical systems, including laser cavities, photo-absorption processes, and laser soldering or welding applications. By simulating how optical power is distributed and absorbed within a system, designers can clearly understand where the energy goes, identify inefficiencies or hot spots, and make informed design modifications before physical prototyping.
This article presents two practical examples demonstrating how volume-based energy absorption simulation can be applied effectively.
Example 1: Laser Flash Pump Cavity Simulation
This first example demonstrates the use of a Detector Volume object in a simplified laser flash pump cavity model.
System Description
- The laser cavity is formed by two toroidal mirrors located at opposite ends of the cavity (objects 3 and 4).
- Near each mirror, a Source Tube emits rays to simulate the flash pump lamps (objects 1 and 2).
- At the center of the cavity, a Cylinder Volume object (object 6) represents the laser crystal.
- A Detector Volume object (object 5) overlaps the laser crystal volume.
Detector Volume Object Overview
The Detector Volume records both incident and absorbed energy from non-sequential source rays as they pass through three-dimensional volume pixels, known as voxels.
Key capabilities include:
- Recording incident flux per voxel
- Recording absorbed flux per voxel
- Calculating absorbed flux per unit volume
Detector Volumes:
- May be transparent or assigned any valid optical material
- Can overlap, nest within, or straddle other objects
- Can coexist with refractive, reflective, absorbing, gradient-index, or scattering objects
Absorption Modeling in the Laser Crystal
In this example:
- The Detector Volume is a rectangular 3D grid of voxels
- The Detector Volume overlaps a Cylinder Volume made of BK7 glass
- Transmission (absorption) data for BK7 is defined in the Materials Catalog
Because of this overlap, the software records absorbed energy per voxel, allowing visualization of:
- Pump light absorption distribution
- Energy concentration zones
- Regions of inefficient pumping
This information is extremely valuable for optimizing crystal dimensions, pump geometry, and mirror placement.
Example 2: Biomedical Tube Array Absorption Simulation
The second example is based on a real biomedical project, simulating light absorption in a tube (well) array illuminated by an LED array.
Application Context
- Each tube contains a biomedical liquid with known absorption characteristics
- An LED array illuminates the tube array from above
- Detector Volumes are placed within each tube
The simulation visualizes:
- Absorbed energy in each well
- Relative intensity differences between wells
- Potential non-uniformity caused by LED placement or optics
Simulation Validation
The simulation results were compared with experimental measurements, and the absorbed energy distributions showed excellent agreement with real-world test data. This confirms that volume-based absorption simulation is a reliable method for:
- Biomedical photonic analysis
- Light dosage control
- Optical system optimization
Conclusion
Volume-based absorption simulation provides powerful insight into where optical energy is deposited inside complex systems. Whether used for laser pumping efficiency or biomedical illumination analysis, Detector Volume–based methods enable engineers to:
- Predict absorption behavior accurately
- Identify hot spots or inefficiencies
- Reduce costly trial-and-error experimentation
If you require further technical details or support for absorption modeling, laser systems, or illumination simulation, feel free to contact us for technical consulting services.