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Introducing the LDC500 SeriesLaser Diode Controller — highly stable, low-noise current sources, with an integrated temperature controllers — all at very affordable prices.
The LDC500 series are the ideal instruments for controlling the
current and temperature of your laser diodes. They have the performance
and features you expect from instruments costing twice as much.
The LDC501 has up to 500 mA of output current with less than 1µA
of rms noise, while the LDC500 has up to 100 mA of current and less
than 0.3µA of noise.
With a low-noise current source, a 36 W high-precision temperature controller, and standard computer interfaces including Ethernet, the LDC500 series is the right choice for your laser diode testing and control applications.
Easy-To-Use Interface
The LDC500 series have an intuitive user interface, and many first
time users will be able to operate the instruments without having
to crack open the manual (although we do recommend reading the manual).
Unlike competitive models, the LDC500 series controllers have a
dedicated front-panel display for parameter entry. You don’t
have to sacrifice monitoring temperature or current to simply change
an instrument setting — you have a separate two-line, blue
alpha-numeric display for that. In addition, bright 5-digit green
LED displays constantly monitor current and temperature, and are
large enough to easily read from anywhere in the lab.
Laser Diode Protection
Multiple laser diode protection features, including slow start turn-on, adjustable current limits, and adjustable compliance voltage, keep your laser diodes safe when unexpected events occur. Fast clamping and shut down provide extra protection against intermittent contact with the laser. Combined, these features provide trouble-free, safe control of your
laser diode.
Linear Power Supplies
Independent linear power supplies are used for the laser diode controller and the temperature controller. The supplies are designed with a magnetically shielded toroidal transformer, and provide ultra-clean, stable isolated power.
Computer Control
Remote operation of the LDC500 series is supported with GPIB, RS-232
and Ethernet interfaces. All instrument functions can be controlled
and read over any of the interfaces. Up to nine complete instrument
configurations can be saved in non-volatile RAM and recalled at
any time. A TTL trigger output is also available to synchronize
other test equipment.
Stable Laser Diode Controller
To ensure a stable optical output from your laser diode, the LDC500
series LD controllers were designed to deliver noise-free, precision
operation. They are accurate to ±0.01 % FS, have automated
testing setups, noise is as low as 0.2 µA rms, and they meet
a drift specification of 10 ppm/°C.
The controller have two modes of operation for the laser diode:
constant current and constant power. Constant current mode (CC)
programs the source to a precise DC amplitude. Alternatively, the
constant optical power mode (CP) servos the current source to maintain
a constant signal on a monitor photodiode. Both control modes allow
you to add an external modulation signal, with adjustable bandwidth
up to 1.2 MHz (in CC mode) or 10 kHz (in CP mode).
Another convenient feature that the LDC500 series offers is a fully
programmable photodiode bias voltage. You can set the bias between
0 and 5 V from the front panel, or remotely using one of the computer
interfaces.
Bumpless Transfer
A unique feature of the LDC500 series is Dynamic “Bumpless”
Transfer between CC and CP modes. This feature means you don’t
have to shut down your laser to switch modes — simply press
the Current/Power button.
36 W Temperature Controller
The LDC500 series integrated 36 W temperature controller lets you adjust temperature with 0.001 ºC resolution, and measure temperature with 0.01 ºC accuracy (with a calibrated sensor). It maintains a typical stability of 0.0005 ºC/ºC with respect to room temperature, and has a very wide temperature control range.
The TEC controller also has two modes of operation: constant temperature mode (CT) controls the TEC current to maintain a fixed temperature (or raw sensor value), while constant current mode (CC) operates the TEC at a fixed current. Thermistor, RTD and IC sensors are all supported.
The LDC500 serieshas an auto-tuning feature which automatically
optimizes the PID loop parameters of the controller. Of course,
full manual control is provided too. Dynamic "Bumpless"
transfer between CT and CC modes for the TEC is also easy —
just press the Temp/Current button.
Online Thermistor Calculator
About Thermal Stability
Temperature fluctuations in a typical laboratory environment can often exceed several degrees Celsius over the course of a day. Small temperature changes can mean significant current changes in your laser diode if your controller is not up to the task.
The LDC500 and LDC501 have a temperature coefficient of 10 ppm/°C, which is a factor of five better than competing models, making it the ideal controller for precision laser diode experiments.
The graphs to the right demonstrate the temperature performance of the LDC500. Over a 24 hour period, the ambient temperature change in the laboratory exceeds two degrees Celsius. Note that the output current deviation of the LDC after warm-up is stable to better than ±10 ppm.
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