Precilaser

Python interface for precilaser devices

Implements a python interface using pyserial for 3 Precilaser devices:

• Precilaser Fiber DFB
• Precilaser Amplifier
• Precilaser SHG Amplifier

Installation

pip install precilaser or install directly from source.

This project is managed with uv. For development, clone the repository and run uv sync to create a virtual environment with all dependencies (including the test tooling), then uv run pytest to run the tests and uv build to build the sdist/wheel.

Implemented Functionality

Precilaser Fiber DFB

• status
  retrieve the laser status, in a dataclass (with some of the boilerplate code removed; see status.py for more detail):

    @dataclass
    class SeedStatus:
      status_bytes: bytes
      endian: str
      temperature_set: float # grating temperature setpoint [C]
      temperature_act: float # grating temperature [C]
      temperature_diode: float # [C]
      current_set: int # [mA]
      current_act : int # [mA]
      wavelength: float # [nm]
      piezo_voltage: float # [V]
      emission: bool
      power: int
      run_hours: int
      run_minutes: int
  

• temperature_setpoint
  get or set the grating temperature in C
• piezo_voltage
  get or set the piezo voltage, from 0 V to 5 V
• _get_serial_wavelength_params
  retrieve the parameters required to reconstruct the wavelength from the grating temperature
• wavelength
  calculate the wavelength from the retrieved parameters and the grating temperature

Precilaser Amplifier

• status
  retrieve the amplifier status, in a dataclass (with some of the boilerplate code removed; see status.py for more detail):

  @dataclass
  class AmplifierStatus:
    status_bytes: bytes
    endian: str
    stable: bool
    system_status: SystemStatus
    driver_unlock: DriverUnlock
    driver_current: Tuple[float, ...]
    pd_value: Tuple[int, ...] # internal photodiode values in arb. units
    pd_status: Tuple[PDStatus, ...]
    temperatures: Tuple[float] # internal temperatures of amplifier stages etc.
  
  @dataclass
  class SystemStatus:
    status: int
    pd_protection: Tuple[bool, ...]
    temperature_protection: Tuple[bool, ...]
    fault: bool
  
  @dataclass
  class DriverUnlock:
    driver_unlock: int
    driver_enable_control: Tuple[bool, ...]
    driver_enable_flag: Tuple[bool, ...]
    interlock: bool # true if the interlock is ok
  
  @dataclass
  class PDStatus:
    status: int
    sampling_enable: bool
    hardware_protection: bool
    upper_limit_enabled: bool
    lower_limit_enabled: bool
    hardware_protection_event: bool
    upper_limit_event: bool
    lower_limit_event: bool
    fault: bool
  

• current
  get or set the amplifier current [A]
• enable()
  enable the amplifier
• disable()
  disable the amplifier
• save() save amplifier settings to ROM
• enable_power_stabilization()
  enable power stabilization mode; varies the amplifier current to keep the output power constant
• disable_power_stabilization() disable power stabilization mode

Precilaser Amplifier

A subclass of the Amplifier, includes all Amplifier functionality plus additionally:

• shg_temperature get or set the shg crystal temperature [C]

Example

The devices can be used directly or as a context manager; the context manager guarantees the serial port is closed when the block exits.

from precilaser import SHGAmplifier

with SHGAmplifier("COM50", address=0) as amp:
    # change the SHG crystal temperature
    amp.shg_temperature = 73.15

Or, without the context manager, close the port explicitly when done:

from precilaser import SHGAmplifier

amp = SHGAmplifier("COM50", address=0)
amp.shg_temperature = 73.15
amp.close()