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d2:offset_phase_lock_servo [2018/12/05 16:34] – [Table] Michael Radunsky | d2:offset_phase_lock_servo [2018/12/05 16:35] – [Understanding the Transfer Function] Michael Radunsky |
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=====Understanding the Transfer Function===== | =====Understanding the Transfer Function===== |
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The charge pump in the OPLS outputs a signal proportional to the phase-error and the transfer function is as shown in <imgref opls_side_panel>. However, the OPLS will typically be used to control a //frequency//-tunable device (such as a laser). In this configuration, the effective loop filter is not the one shown in <imgref opls_side_panel>, but includes a extra integration corresponding to converting the phase-error input to a frequency error. Thus, ω<sub>I </sub>sets the frequency transition from single-integration to double-integration and ω<sub>I</sub> from single-integration to proportional feedback. It is important to understand this 'hidden' integrator when configuring the loop filter parameters. | The charge pump in the OPLS outputs a signal proportional to the phase-error and the transfer function is as shown in <imgref opls_side_panel>. However, the OPLS will typically be used to control a //frequency//-tunable device (such as a laser). In this configuration, the effective loop filter is not the one shown in <imgref opls_side_panel>, but includes a extra integration corresponding to converting the phase-error input to a frequency error. Thus, ƒ<sub>I </sub>sets the frequency transition from single-integration to double-integration and ƒ<sub>I</sub> from single-integration to proportional feedback. It is important to understand this 'hidden' integrator when configuring the loop filter parameters. |
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=====Calculating Phase Noise ===== | =====Calculating Phase Noise ===== |