Calculate how much radiant power goes through an optical system

[rp895]

Hi,
I have to do a rediometric analysis on an optical system , basically calculate how much radiant power goes through an optical system from the target to the detector, passing through multiple lenses and prisms then to the detector. I am having some problem with radiance and irradiance calculations going through a series of lenses and especially the prism.

Any help will be appreciated!
rp895

 

[Claude Bile]

The rule of thumb is that you lose 4% (for visible wavelengths) at each component due to Fresnel reflections, unless of course there are antireflection coatings present, in which case the 4% will be a much lower figure.

If you know the loss in dB at each component, all you need to do is add all the losses in dB to get the total loss.

This is of course making the assumption that no light is lost due to bad alignments etc.

Claude.

 

[astrokreng]

Hello rp895,

Calculating the amount of radiant power that goes through an optical system can be a complex task, as it involves understanding the properties of light and how it is affected by different materials and components within the system. However, here are some general steps that can guide you in your analysis:

1. Start by understanding the basic principles of radiometry and photometry. Radiometry deals with the measurement of electromagnetic radiation, while photometry focuses on the measurement of visible light. This will help you understand the units and concepts used in calculating radiant power.

2. Next, determine the spectral characteristics of the light source and the target, as well as the transmission properties of the lenses and prisms in your system. This will help you determine the spectral range of interest and the amount of light that is being transmitted through each component.

3. Use the equations for radiance and irradiance to calculate the radiant power at each point in the system. Radiance is the amount of radiant power per unit solid angle per unit projected area, while irradiance is the amount of radiant power per unit area. These equations take into account factors such as distance, angle, and solid angle.

4. Take into account the properties of the lenses and prisms, such as their transmission and reflection coefficients, to calculate the amount of light that is transmitted through each component.

5. Finally, add up the radiant power at each point in the system to determine the total amount of radiant power that goes through the optical system.

It is important to note that the calculations may vary depending on the specific setup and components of your optical system. It may also be helpful to consult with a radiometry expert or refer to literature on similar systems for guidance. I hope this helps and good luck with your analysis!