Overview

Two diode lasers DL100 with control modules in 19" rack housing
Two diode lasers DL100 with control modules in 19" rack housing

DL100 | DL110

Precise control of diode lasers and the acquisition of measured values

The DL100 / 110 series offers modules for the precise control of diode lasers and for acquisition of measurement data.

The different modules of the series are plugged-in into the DC100 / 110 rack, which is available in several versions with different widths and heights.

For standard applications normally the modules DC (power supply and monitoring module), DCC (diode current control) and DTC (temperature control) are sufficient.

This modular system has been developed for TOPTICA Photonics AG and can be bought there.In particular, the diode laser DL100 that is controlled by the DL100/110 system ca be bought at TOPTICA Photonics AG.

Technical Data

Diode Control Bus Modul DCB

The DCB module is an interface module providing direct access to the internal analog control signals of the DC100/110 rack. 

  • Most of the rack-internal parameters can be read out as set values and as actual values
  • Allows an external control of the DL system via a PC with DA-/AD-interface card

DL 100 - DCB

Specifications

  • Allows data transfer to and from a PC by means of a standard Sub-D25 cable
  • Parameters can be read out as well as the system can be controlled by a computer
  • Mostly all internal parameters can be read out as set values (Xset) and as actual values (Xact)
  • All control wires are decoupled via resistors or buffers in order to avoid disturbances in the system
  • Four control channels can be controlled from extern (configurable via jumpers)
  • One selectable parameter can be supervised or fed in via a BNC-connector

Technical data

  • Standard input impedance for reading out of parameters: 10 kΩ
  • Input sensitivities for the electrical parameters:       

Current of the DCC100/500 mA:
0 V = 0 mA
1 V = 10 mA

Current of the DCC100/ 3 A:
0 V = 0 mA
1 V = 100 mA

Temperature:
0 V = 0 °C
1 V = 10 °C
1 V = 10 °C

Diode Temperature Control Module – DTC

The DTC module is a highly stable temperature control unit for laser diodes, like used in spectroscopic applications for example.

Available in three versions:

a) For driving of a cooler / heater by means of a thermo-electric element (Peltier element)

b) As SVL version (set-point velocity limitation) with highly-precise defined velocity limitation, like mostly required for frequency doubling crystals (predefined maximum temperature change per time) 

c) For the temperature control of a small mass e.g. a DFB-laser diode

Maximum output power 30 W

DL 100 - DTC

Specifications

  • Different temperature sensors are supported (thermistor 10 kΩ/neg, AD 590, etc.)
  • Temperature (Tset) adjustable via range switch (coarse) and 10-turn potentiometer (fine)
  • Minimum and maximum temperatures (Tmin, Tmax) adjustable via precision trimming potentiometers
  • Control of the thermo-electric element via SubD9-Verbinder
  • Maximum current for the thermo-electric element (ITECmax) adjustable via precision trimming potentiometer
  • Polarity switch for adaptation to different thermo-electric elements
  • SVL version (set-point velocity limitation) with very precisely defined velocity limitatio

Technical Data

  • Maximum output current for the thermo-electric element (ITECmax): 0 to 5 A
  • Maximum output power: 30 W
  • Maximum temperature (Tmax): 0 to + 50 °C (special version – 50 to + 150 °C)
  • Minimum temperature (Tmin): 0 to + 50 °C (special version – 50 to + 150 °C), with Tmin < Tmax
  • Extremely low drift (with DL100 laser head < 2 mK)

Lock-In Regulator Module – LIR

The LIR module allows the active locking of the laser frequency of a diode laser to a desired wavelength.

This module contains mainly three functions: 

  • Internal modulation source
  • Lock-in amplifier
  • PID-regulator

Typically, these functions are used to stabilize the laser towards an atomic absorption line or a cavity-resonance (top-of-fringe-stabilization).

DL 100 - LIR

Spezifikationen

  • Modulation signal selection between internal modulation source and external signal possible
  • Signal form of the internal modulation source selectable between sine and triangular
  • Frequency of the internal modulation source adjustable via switch (coarse) and potentiometer (fine)
  • Amplitude of the internal modulation source adjustable
  • Phase of the modulation signal adjustable via switch (coarse) and potentiometer (fine)
  • Decoupling and amplification of the lock-in input signal adjustable
  • (DC-decoupling or two different low pass filters)
  • Lock-in amplifier (phase detector) with integrated, adjustable low pass filter
  • Offset of the lock-in signal adjustable
  • Switchable PID-regulator with relock mechanism and adjustable P-, I- and D-terms
  • Output voltage of the PID regulator adjustable•Internal and external offset can be added to the output signal of the module per switch
  • Internal offset for the output signal is adjustable
  • External supervision possible by selection of the internal signals as monitor signal

Technical Data

  • Modulation frequency: 0.6 Hz to 14 kHz
  • Modulation amplitude: 0 V to 10 VSS
  • Cut-off frequencies of the high pass filters for decoupling of the lock-in input signal: 16 Hz, 160 Hz
  • Cut-off frequency of the low pass filter in the lock-in amplifier: 16 mHz to 16 kHz
  • Amplification of the external lock-in input signals: 1 to 3000
  • Lock-in bandwidth: 16 mHz up to 16 kHz
  • Amplitude range of relock mechanism: – 5 V to + 5 V

Proportional-Integral-Differential Regulator Module PID

The PID module is a universal proportional-integral-differential regulator.

  • Adjustable P-, I- and D-terms
  • High-voltage output with 0 to 150 V (optionally as well with low-voltage output ± 10 V)

Application areas are e.g. the stabilization of a diode laser towards a flank of an atomic resonance or an Airy peak of a Fabry-Perot-interferometer, the stabilization of a laser resonator by driving a piezo actuator, or the compensation of disturbances like acoustic noise, vibrations and temperature changes.

DL 100 - PID

Specifications

  • Reset voltage (set point) and search speed of the PID-regulator adjustable
  • P-, I- and D-term each adjustable via potentiometers•Switchable relock function•Indication of the lock status via LEDs (search, unlock, relock)
  • External modulation or internal modulation possible (via SC module)
  • Output voltage adjustable via precision potentiometer•Inverted output voltage per switch selectable
  • External supervision possible by selection of an internal signal as monitor signal
  • Optionally as well with low-voltage output (± 10 V, 20 mA)

Technical Data

  • Output voltage: 0 V to 150 V, maximum 30 mA and maximum 8 W
  • Optionally with low-voltage output: – 10 V to + 10 V, maximum 20 mA
  • Monitor signal: – 10 Volts to + 10 Volts

 

Pound-Drever-Hall Detector Module PDD

The PDD module contains all functions for laser stabilization with the HF side band modulation technique (Pound-Drever stabilization). 

  • Output voltage with defined frequency for HF modulation (typically 20 MHz)
  • bandwidth also suitable for resonators with high finesse
  • Available with one or two phase detector and error signal channels

DL 100 - PDD

Specification

  • Detection of the phase delay (dispersion) by phase comparison of a base band with a side band and generation of a Pound-Drever-signal
  • Internal oscillator with a defined oscillation frequency as generator for the base band signal
  • Output voltage of the internal oscillator externally available
  • Output voltage of the internal oscillator adjustable via potentiometer
  • Amplification of the photo diode input signal adjustable via potentiometer
  • Additional relative phase adjustable via potentiometer
  • Pound-Drever error signal externally available
  • Optionally as well with two phase detector and error signal channels

Technical Data

  • Output frequency of the internal oscillator: 20 MHz (standard, other frequencies from 5 to 40 MHz on request)
  • Output amplitude of the internal oscillator: adjustable to up to – 4 dBm
  • Output impedance of the internal oscillator: 50 Ω (standard, adaptation possible via internal resistor)
  • Amplitude of the second harmonic: typically < – 30 dBc at an output amplitude of – 4 dBm
  • Maximum input amplitude of the photo detector signal: – 7 dBm
  • Maximum output voltage of the error signal: – 0.8 V to + 0.8 V
  • Output voltage of the error signal with a regulator bandwidth of up to 1 MHz

Scan Controller Module – SC

The SC module serves for scanning the laser frequency of an external-cavity diode laser head DL100.

The DL100 is tuned by moving a grating via a piezo element.

  • High-voltage output
  • Triggering by external signal possible

Thus, a fine tuning of the wavelength of an external-cavity diode laser within the single-mode scan range is possible.

DL 100 - SC

Specification

  • Signal form symmetry of the output signal can be adjusted (triangular or sawtooth shape)
  • Wavelength fine tuning of a diode laser within the single-mode scan range
  • Scan frequency adjustable via range switch (coarse) and potentiometer (fine)
  • Output amplitude adjustable via logarithmic potentiometer
  • Offset can be added and adjusted via a 10-turn potentiometer
  • Output for monitoring the internal trigger signal
  • Input for external trigger signal
  • Delay of the trigger signal adjustable via potentiometer
  • Internal feed forward signal for the laser diode current adjustable via trimming potentiometer (scan ratio between the output voltage of the SC, i.e. the piezo voltage, and the laser diode current)

Technical Data

  • Scan frequency: 0.01 Hz to 10 kHz
  • Output amplitude: -10 V to +150 V, maximum 30 mA
  • Offset amplitude: – 10 V to 150 V.