SUServoModulatedLaser#

Class Arguments

Argument	Type	Default Value
default_kp	TFloat
photodiode	Photodiode
modulator	LightModulator
laser_source	LaserSource
default_ki	TFloat	0.0
default_ki_limit	TFloat	0.0
start_stabilized	TBool	True
switch	Switchable	None
fm_device	TStr	mod
am_device	TStr	mod
src_transmission	TFloat	1.0
zero_freq	TFloat	None
power	TFloat	0.001

Bold arguments are mandatory. For more documentation on the listed arguments refer to the class definition below. If parameters appear in this list but not in the class definition below, please recursively check the linked base classes for the definition of the parameter.

Inheritance Diagram

Example Component Dictionary

   {
    "suservo_example": {
        "classname": "atomiq.components.sinara.suservo.SUServoModulatedLaser",
        "arguments": {
            "default_kp": "<mandatory parameter (TFloat)>",
            "photodiode": "<mandatory parameter (Photodiode)>",
            "modulator": "<mandatory parameter (LightModulator)>",
            "laser_source": "<mandatory parameter (LaserSource)>",
            "default_ki": 0.0,
            "default_ki_limit": 0.0,
            "start_stabilized": true,
            "switch": null,
            "fm_device": "mod",
            "am_device": "mod",
            "src_transmission": 1.0,
            "zero_freq": null,
            "power": 0.001
        }
    }
}

Class Description

class atomiq.components.sinara.suservo.SUServoModulatedLaser(default_kp, default_ki=0.0, default_ki_limit=0.0, *args, **kwargs)

Bases: ContinuouslyStabilizedModulatedLaser

A Laser with intensity stabilization realized by the SUServo

The SUServo realizes a PI servo controller in hardware with an update time inteval of 1.3us, leading to a maximum analog bandwith of >500kHz. To achieve this a Sampler (8 analog in) is bundled in the gateware with two Urukuls (2 x 4 DDS channels).

With this class, the SUServo can be used in open loop as well as in closed loop mode. Use the stabilize() function to switch between open and closed loop mode. When switching from closed to open loop, the last output power on the DDS channel will be hold.

Parameters:

modulator -- The modulator (most likely an AOM) that is driven by the SUServo. The Modulator given here must be of a class derived from :class:RFLightModulator and the rfsource of the modulator must be of the class :class:SUServoChannel.
photodiode -- The photodiode monitoring the laser. The photodiode must be of a class derived from :class:AnalogPhotodiode and the photodiode's :param:adc_channel must be of the class :class:SUServoADCChannel.
default_kp (TFloat) -- default proportional (P-) part for the SUServo loop. Values should be negative.
default_ki (TFloat) -- default integral (I-) part for the SUServo loop. Values should be negative. (default 0.0)
default_ki_limit (TFloat) -- default limit for I-part of the SUServo loop. 0.0 means unlimited. (default 0.0)

A Switchable has one ore more channel(s) that can be switched on or off

set_servo_parameter(adc_channel, kp, ki, ki_limit, delay=0.0)

Set servo loop parameters

Parameters:

kp (TFloat) -- proportional (P-) part for the SUServo loop. Values should be negative.
ki (TFloat) -- integral (I-) part for the SUServo loop. Values should be negative. (default 0.0)
ki_limit (TFloat) -- limit for I-part of the SUServo loop. 0.0 means unlimited. (default 0.0)
delay (TFloat) -- delay between switching on the laser an the servo loop becoming active

set_power(power)

Set the output power of the laser

If the SUServo is in open loop mode, this sets the amplitude of the DDS channel. If the SUServo is in closed loop mode, it sets the photodiode value the servo loop should target. If the photodiode is calibrated the power argument should be given in the calibrated units.

Parameters:: power (TFloat) -- the power the laser should be set/stabilized to. In open loop mode it takes the DDS amplitude (0..1). In closed loop mode it takes the target value on the photodiode for the servo loop. If the photodiode is calibrated the power should be given in the calibrated units (e.g. mW).

arb(duration, samples_amp=[], samples_power=[], samples_freq=[], samples_det=[], samples_phase=[], repetitions=1, prepare_only=False, run_prepared=False, transform_amp=<function identity_float>, transform_freq=<function identity_float>, transform_phase=<function identity_float>)

Play Arbitrary Samples from a List

This method allows to set the output amplitude, frequency an phase according to the values specified in respective lists. The whole sequence is played in the specified duration. The pattern store in the sample list can also be repeated.

We supports a scheme to prepare the arb function before it is actually used. If that is needed, run this function with prepare_only = True when the arb should be prepared and with run_only = True when the prepared arb should be played. In both calls the other parameters have to be passed.

Parameters:

samples_amp (TList(TFloat)) -- List of amplitude samples. If this list is empty (default), the amplitude is not modified.
samples_power (TList(TFloat)) -- List of power samples. If this list is empty (default), the amplitude is not modified. This overwrites samples_amp.
samples_freq (TList(TFloat)) -- List of frequency samples. If this list is empty (default), the frequency is not modified.
samples_det (TList(TFloat)) -- List of frequency samples relative to the zero frequency. If this list is empty (default), the frequency is not modified. This overwrites samples_frequency
samples_phase (TList(TFloat)) -- List of phase samples. If this list is empty (default), the phase is not modified.
duration (TFloat) -- The time in which the whole sequence of samples should be played back [s].
repetitions (TInt32) -- Number of times the sequence of all samples should be played. (default 1)
prepare_only (TBool) --
run_prepared (TBool) --

ramp(duration, frequency_start=- 1.0, frequency_end=- 1.0, amplitude_start=- 1.0, amplitude_end=- 1.0, power_start=- 1.0, power_end=- 1.0, ramp_timestep=- 1.0, ramp_steps=- 1)

Ramp frequency and/or power/amplitude over a given duration.

Parameters default to -1 to indicate no change. If the start frequency/amplitude is set to -1, the ramp starts from the last frequency/amplitude which was set.

Either power or amplitude can be given to ramp the intensity of the laser. If power is given, it overwrites the value for the amplitude

This method advances the timeline by ´duration´

Parameters:

duration (TFloat) -- ramp duration [s]
frequency_start (TFloat) -- initial frequency [Hz]
frequency_end (TFloat) -- end frequency [Hz]
amplitude_start (TFloat) -- initial amplitude [Hz]
amplitude_end (TFloat) -- end amplitude [Hz]
power_start (TFloat) --
power_end (TFloat) --
ramp_timestep (TFloat) --
ramp_steps (TInt32) --

set_frequency(frequency)

Set the absolute frequency of the light after modulation

Parameters:: frequency (TFloat) -- Absolute frequency of the light after modulation in Hz