I'm currently reviewing Spontaneous-Parametric-Down-Conversion (SPDC) and Second-Harmonic-Generation (SHG) inside optical cavity. I have found some information on them such as the different type (Linear/standing wave and running wave) and configuration (monolithic, semi-monolithic, standard, ring). Each have their pros and cons that I already summarized in a nice table. I am to build a new experiment for squeezed states generation and my first task is to decide what configuration to use.
I already know I'll be using PPKT crystal, and standard Fabry-Perot cavities for SHG and SPDC (monolithic one lacks degrees of freedom) and potentially ring cavity. I know I'll need very small transmission coefficients for the mirrors to set the bandwidth of the cavity at 10MHz (atomic transition of Rb) and that the Finesse will be pretty large (assuming cavity length in the centimeters). But one thing I'm not sure of for example, is how to choose the length of the cavity? I cannot just take for granted what I could find in other papers, I need to state why a specific length and not another one (why 120cm and not 50 for example).
I'm not an experimentalist so I don't really have an intuition on this kind of issues. And usually, papers don't mention the details of the reasoning behind the choice of a specific cavity, and its characteristics. For instance, it took me a good month to gather all the information I have on crystals and cavity.
