Holographic grating - can we calculate efficiency for each order?

In summary, the conversation is about using the basic grating equation to model diffraction angles and calculate dispersion for different angles of incidence and broadband sources. There is uncertainty about how the angle of incidence affects the power going into each order and whether there is a dependence on efficiency. Grating efficiency is a complex function of incident polarization and groove shape, and there is no underlying analytic theory. One resource for more information is chapter 9 of the Newport gratings handbook and a paper on opticsinforbase.org. In some cases, the shape of the grating may only allow one order to exist, and the higher orders do not exist due to larger diffraction angles. A suggested paper to explore is R.E. Bell's "Exploring a
  • #1
Turksen
4
0
Hi,

I'm new to working with gratings. From using the basic grating eqn., I'm able to model the diffraction angles for each order with different angles of incidence upon the grating and I can calculate the dispersion given a broadband source with known minimum and maximum wavelength.

However, I'm unsure how the angle of incidence affects the power going into each order. I think the n=+1 order is usually the most efficient, although is there a dependence upon the incidence angle / diffraction angle for efficiency?

Thanks
 
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  • #4
In the case of some volume phase gratings I've seen, the shape of the grating only allows one order to exist. The higher orders have a larger than 90 degree diffraction angle and therefore don't exist. You might check out: R.E. Bell. Exploring a transmission grating spectrometer. RSI 75 10 (2004)
 
  • #5
for your question!

Yes, it is possible to calculate the efficiency for each order of a holographic grating. The efficiency of a diffraction grating is determined by factors such as the grating spacing, the wavelength of light, and the angle of incidence. The efficiency of each order can be calculated using the grating equation, which relates the angle of diffraction to the grating spacing and the wavelength of light. However, the efficiency can also be affected by the polarization of the incident light and the properties of the grating material.

To accurately calculate the efficiency for each order, it is important to consider the angle of incidence and the diffraction angle. As you mentioned, the n=+1 order is usually the most efficient, but this can vary depending on the angle of incidence and the properties of the grating. In general, the efficiency of the higher orders decreases as the angle of incidence increases, while the efficiency of the lower orders decreases as the angle of incidence decreases.

Additionally, the efficiency can also be optimized by adjusting the grating spacing and the angle of incidence. This can be done through rigorous simulations or experimental measurements. Overall, the efficiency of each order can be accurately calculated by considering all the relevant factors and optimizing the grating design for the desired performance.
 

FAQ: Holographic grating - can we calculate efficiency for each order?

What is a holographic grating?

A holographic grating is a type of optical component that is used to disperse light into its component wavelengths. It consists of a series of closely spaced parallel lines that act as a diffraction grating, causing light to be split into different orders of diffraction.

How does a holographic grating work?

A holographic grating works by using the principles of diffraction and interference. When light passes through the grating, it is diffracted into different orders depending on the spacing between the lines. This creates a spectrum of colors, with shorter wavelengths being diffracted at larger angles than longer wavelengths.

Can we calculate the efficiency for each order of a holographic grating?

Yes, it is possible to calculate the efficiency for each order of a holographic grating. This can be done using the grating equation, which takes into account factors such as the incident angle, the wavelength of light, and the spacing of the grating lines.

What factors affect the efficiency of a holographic grating?

The efficiency of a holographic grating is affected by several factors, including the spacing of the grating lines, the angle of incidence of the light, and the wavelength of the light. Additionally, the quality of the grating and any imperfections in its construction can also impact the efficiency.

How is the efficiency of a holographic grating measured?

The efficiency of a holographic grating is typically measured by comparing the intensity of the diffracted light to the intensity of the incident light. This can be done using a spectrometer or other specialized equipment. The efficiency is then calculated by dividing the intensity of the diffracted light by the intensity of the incident light.

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