It is recommended to have a minimum optical density (OD) = 5, for laser safety glasses to handle a Er-doped fiber laser with CW output power of 1 W. Accordingly, the minimum OD required for laser safety glasses for handling a high-power Er-doped laser giving CW output of 5 kW is ___.(Write your answer correct up to 2 decimal places

The optical density (OD) is a logarithmic scale that measures how much a filter reduces light intensity. The formula to calculate OD is:

OD = -log10(I/I0)

where I is the transmitted intensity, and I0 is the incident intensity.

In this case, we know that an OD of 5 is sufficient for a 1 W laser. This means that the glasses reduce the light intensity by a factor of 10^5.

If we increase the power of the laser to 5 kW (or 5000 W), we need to find the new OD that reduces the light intensity by the same factor.

Since the OD is a logarithmic scale, an increase in power by a factor of 5000 means we need to add log10(5000) to the original OD.

log10(5000) is approximately 3.70.

So, the new OD is 5 (the original OD) + 3.70 = 8.70.

Therefore, the minimum OD required for laser safety glasses for handling a high-power Er-doped laser giving CW output of 5 kW is 8.70.