Can anyone tell me the equation to convert the laser beam intensity to db unit in origin software?
See e.g. https://www.rapidtables.com/convert/power/mW_to_dBm.html for
mW to dBm conversion. The formula P(dBm) = 10 ⋅ log10( P(mW) / 1mW) can be directly entered in Origin (or Excel)
dB is a logarithmic scale but laser beam intensity is measured by Photons per squared cm because it will be difficult. But you can normalize your laser beam intensity of signal by using some famous intensity such as output intensity of laser or unfocused laser beam intensity or by using output laserbeam intensity according to the specification of laser equipment.
dB is the log of a ratio. In electronics or microwave engineering it is always the log of a power ratio, but the power may be specified to be absolute power, relative power, or power per square cm, for instance.
dB is 10 times the log base 10 of a power ratio.
the base power may be specified in the unit, such as dBm (dB above 1 mW) or dBm/m2 (dB above 1 mW/m2)
6 dB means the power increased by a factor of 4. (approx).
6 dBm means a factor of 4 higher than 1 mW, or 4 mW.
6 dBm/m2 means 4 mW/m2
Sometimes voltage is used, but then the ratio as the square root. 6 dB above 1 V/m is 2 V/m, because the power increases as the square of the voltage (or field strength). This is why the 3 dB point is 70% voltage (approx). The 3 dB here really means -3 dB, half the power, or 1/(root 2) of volts.
if the power gets smaller the dB is negative, although some people use words such as gain or loss instead of positive and negative signs. You will often see -20 dB described as 20 dB loss or 20 dB attenuation.
Preangka Roy Preangka, The link below is a conversion from the OpenLab forum:
https://my.originlab.com/forum/topic.asp?TOPIC_ID=3364
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