Electronic – How to generate a 10Ghz signal

I did exactly that in a previous project, I didn't use the open logic analyzer but the bus pirate which uses the same software.

http://s3cu14r.wordpress.com/2011/06/19/basic-rf-sniffing-with-the-bus-pirate/

I used this to decode the protocol for another project that sniffed RKE data.

http://hackaday.com/2009/10/03/garage-door-packet-sniffer/

Hope this helps.

What modulation scheme do you intend to use? (Amplitude modulation, Frequency modulation, Pulse-density modulation, etc.).

What type of waveform is your input signal? (sinewave, pulse, triangle, etc.). Are you trying to convey the input's amplitude, frequency, duty-cycle, and/or phase?

For OOK and other pulse-modulation schemes, the laser-diode/LD current would switch from full off to full on (0mA and 75mA for your LD. The 90mA is an absolute max. spec.), at a frequency or width determined by the modulation signal. For FM, the LD would be driven with a pulse train whose frequency changes according to the modulation signal. For AM, the LD would be biased at 50%, and DC-modulated by the input signal.

For OOK, I would use a simple switched current source:

^{simulate this circuit – Schematic created using CircuitLab}