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TeachSpin Laser Diode Spectroscopy System
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This page contains helpful information about the TeachSpin laser diode spectroscopy apparatus used for the Hyperfine lab.  As of Aug-2025 we have two identical laser diode, photodetector, and vaporcell setups in use.

====== Laser Diode Info ======

===== Room 005 =====
SN : DL320

Resonance Settings As shipped:
  * Current = 50mA
  * Temp = 2.5V on Monitor output = 25deg C.

Resonance Settings in Lab:
  * 4.77V on Monitor output = 47.7mA.
  * T Setpoint = 2.603V on Monitor output.
  * Attenuator setting on Current control = 0.6.



====== Laser Diode Controller ======

TeachSpin Model DL1-A
Serial #'s DL310 and DL320.

Class 3B Laser
780nm
80 mW CW

===== Overview =====

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Fig 1.  Laser Diode Controller Front Panel
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The Laser Diode Controller provides controls for the ECL diode laser, the photodetectors and temperature stabilization of the vaporcell.

The controller electronics are broken up into seven modules, from left to right:

  - Laser Power on off switch.
  - Laser Diode Current Controller
  - Cell Temperature readout and controller.
  - Monitor outputs for the laser diode actual and set point temperatures, and the laser diode current.
  - Ramp Generator.  Controls the laser frequency sweep.
  - Piezo Controller.  Controls for the piezo transducer that moves the feedback grating.
  - Photodetector Controls.  Provides power to up to three TeachSpin photodiode detectors, as well as detector inputs and controls.

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Fig 2. Laser Diode Back Panel.
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The On/Off rocker switch to power the electronics is located on the left side of the back panel.  On the right are connections for the thermocouple readout and the heater control for the Rb Vaporcell.  The D-type connector on the right connects to the laser diode.  All of the physical connections to the laser diode and the grating feedback are made through the D-type cable.  None of the front panel connectors go directly to the diode itself.

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Fig 3.  Front panel connections for laser frequency control.
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Figure 3 shows the connections necessary for controlling the frequency sweep of the laser.  The Ramp Output of the Ramp Generator connects to both the Modulation Input of the Current Control, and the Modulation Input of the Piezo Controller.  

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Fig 4.  Schematic showing connections for typical usage.
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