How to find peak power at 1550nm using an optical meter? I have a setup of tunable laser source at 1550nm connected to a spectrometer(Can't publish the name of spectrometer). The spectrometer has a range of 1510-1595 nm. The graph shows wavelength vs amplitude. The amplitude is in terms of intensity which is not an standard unit.
I am trying to convert the amplitude in terms of dBm or watts. Something like a table amplitude and its equivalent dBm. I have an optical meter but the value shown in optical meter is average power. I have to find the amplitude at 1550nm alone. I have an another optical spectrum analyzer(old model from Agilent)using which I could see the entire spectrum with power at each frequency (in terms of dBm).
I can have that as reference but I want to find the mathematical way of finding the peak power at 1550nm alone given the spectrum diagram like shown below and an optical meter which could tell me the average power.
INFO: I can vary the power of TLS from -6dBm to -10dBm.
Edit 1: Is there any way to use a tunable laser source to produce a laser pulse with peak power of X dBm (Say -5 dBm) at 1550nm? In general the power we set at tunable laser source, is that integrated power or peak power?
 A: The y-axis shows the number of counts.
Divide the peak power value measured with your watt meter with the number of counts shown in the above spectrogtaph to find the resolution per count e.g. 3W/14400 counts ===>  208.3μW/(one count).
If you watt meter shows not peak power but instead RMS average power then multiply its reading with √2 to find P(peak).
Use an automatic tool like this here to find corresponding dBm values (be warned dBm units are used usually for indicating average RMS power and not peak power. If you must so, then you have to indicate this that it is dBm(peak) values).
A: Likely your power meter is showing you the integrated power, i.e. all the power in your laser beam, including all frequencies. So integrate the counts measured by your spectrometer and call that $C$. Then if your power measurement is $P$ (in whatever units), the ratio $P/C$ is the scaling factor for your spectrum.
Keep in mind that you can’t measure a power at exactly 1550 nm; it’ll always be with regard to some bandwidth, limited by the resolution of your system.
