Responsivity and QE Calculator

Reflectivity for Desired Responsivity

Calculate the required reflectivity for a desired responsivity of the sensor. First, the theoretical responsivity is calculated for a sensor with 100% external quantum efficiency, then given the desired responsivity the required reflectivity is calculated.

This calculator is useful to understand the limitations of responsivity for semiconductor photodiodes.

This model uses the Linear Responsivity Relationship to correct for off-peak response. This is valid for wavelengths below the peak to within 10% percent.

This simplified model is valid for a monochromatic signal, such as from a laser.

To use this calculator

1. Gather system inputs and enter into fields.
2. Gather sensor specifications and enter into fields.
   
   

System Inputs Needed

• Input wavelength
• Desired responsivity
  
  

Responsivity for Desired Reflectivity

Calculate the resultant responsivity for a given reflectivity. First, the theoretical responsivity is calculated for a sensor with 100% external quantum efficiency, then given the responsivity from a given reflectivity is calculated.

This calculator is useful to understand the limitations of responsivity for semiconductor photodiodes.

This model uses the Linear Responsivity Relationship to correct for off-peak response. This is valid for wavelengths below the peak to within 10% percent.

This simplified model is valid for a monochromatic signal, such as from a laser.

To use this calculator

1. Gather system inputs and enter into fields.
2. Gather sensor specifications and enter into fields.
   
   

System Inputs Needed

• Input wavelength
• Measured/Modeled/Estimated reflectivity
  
  

Theoretical QE Responsivity and Actual Reported Value

Calculate the theoretical responsivity for a sensor at a given wavelength. With the given sensor responsivity, it calculates the external quantum efficiency (QE). Then, based on Fresnel reflections and assuming an uncoated surface, it calculates the effective internal quantum efficiency (QE).

This calculator is useful to understand the limitations of responsivity for semiconductor photodiodes.

This model uses the Linear Responsivity Relationship to correct for off-peak response. This is valid for wavelengths below the peak to within 10% percent.

This simplified model is valid for a monochromatic signal, such as from a laser.

To use this calculator

1. Gather system inputs and enter into fields.
2. Gather sensor specifications and enter into fields.
   
   

System Inputs Needed

• Input wavelength

From sensor specifications

• Sensor Responsivity
  
  

From the information table

• Approximate material refractive index