Difference between revisions of "Microwave Photonics"
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Direct Modulation: Shot noise : -168 dBm , Thermal noise : -174 dBm. | Direct Modulation: Shot noise : -168 dBm , Thermal noise : -174 dBm. | ||
Laser relative intensity noise(RIN): We do not desire RIN peaks in the passband. | Laser relative intensity noise(RIN): We do not desire RIN peaks in the passband. | ||
| + | shot noise = 2*q*I*R*B. B- Bandwidth, linear with current. | ||
| + | thermal noise = k*T*B. We would like to approach the shot noise limited performance. | ||
| + | RIN is proportional to (I^2). | ||
| + | Noise factor = (effective input noise)/(Thermal noise). Effective input noise is (output noise)/(Gain). | ||
| + | <math>1/3</math> | ||
Revision as of 12:05, 29 March 2010
Basic components: RF -> optical : CW source and a modulator. opical -> RF : Photodetector. OIP3 (output intercept point). Assumption in all math: output noise independent of input power. phase change with thermal conductivity: optical fibre is chosen over RF cable. Direct Modulation: Shot noise : -168 dBm , Thermal noise : -174 dBm. Laser relative intensity noise(RIN): We do not desire RIN peaks in the passband. shot noise = 2*q*I*R*B. B- Bandwidth, linear with current. thermal noise = k*T*B. We would like to approach the shot noise limited performance. RIN is proportional to (I^2). Noise factor = (effective input noise)/(Thermal noise). Effective input noise is (output noise)/(Gain). <math>1/3</math>
