Optical Bandpass filter specification

[OrangeYogi]

Hello,

For optical bandpass filter specification, what do they mean by 0.1nm bandpass filter? What is the equivalent bandpass frequency range of the filter?

Thank you.

 

[berkeman]

Hello,

For optical bandpass filter specification, what do they mean by 0.1nm bandpass filter? What is the equivalent bandpass frequency range of the filter?

Thank you.

Can you post a link to a typical datasheet for an optical bandpass filter?

 

[deskswirl]

Start with the relation between wavelength and frequency:
$$\lambda f=c$$ differentiating gives $$\Delta f=-\frac{c}{\lambda _{0}^{2}}\Delta \lambda $$ The negative sign means that an increase in frequency corresponds to a decrease in wavelength. Assume a wavelength for your carrier frequency, a common one for optical communication purposes is 1550 nm. So the equivalent frequency bandwidth is
$$\frac{\left( 3\cdot {{10}^{8}}\ [GHz\cdot nm] \right)}{{{\left( 1550\ [nm] \right)}^{2}}}\left( 0.1\ [nm] \right)\cong 12.5\ [GHz]$$

Obviously the filter manufacturer will have to specify the filter center frequency for your application.