Benchtop Laser Diode Driver and TEC Controller; Advanced Multi-Level Laser Diode Protection; 16A / 8V driver range; 128W TEC controller

Product Overview:

High Performance Benchtop Laser Diode Driver and TEC Controller

The LDC-337 laser diode controller combines a precision laser diode driver with an integrated thermoelectric temperature controller / TEC controller . These benchtop instruments are designed to safely, precisely bias and thermally stabilize your laser diode. The LDC series controllers are precision-engineered to meet the most demanding laboratory R&D requirements. They are also designed to safeguard the laser diode under test and offer comprehensive protection features to prevent damage to your laser diode.

LDC-337 Laser Diode Protection Features

These units offer the highest level of commercially available laser diode protection to ensure that your laser is protected from damage. Current and voltage limits, upper and lower temperature limits, and a fast shut-down sequence keep your device protected at all times. The following protection features combine to safeguard your laser diode:

• Soft-Start Current Ramping: Gradually increases current to prevent sudden surges that could damage the laser diode. The LDC series units offer the ability for the user to customize the ramp time if desired. The factory default is set to 300 milliseconds.
• Over-current Protection: Prevents excessive current from flowing into the laser diode.
• Over-voltage Protection: Limits the voltage applied to the laser diode.
• Reverse Voltage Protection: Protects against accidental polarity reversal which can permanently damage the diode.
• Thermal Shutdown: Monitors the controller’s temperature and automatically shuts down if over-heating occurs.
• Current Limit: Allows users to define a maximum current threshold to safeguard the diode.
• Compliance Voltage Limit: Ensures the voltage supplied to the diode remains within safe operating conditions.
• Transient Suppression: Filters out power supply transients and electrical noise that could cause instability.
• Short-Circuit Protection: Detects and prevents damage caused by accidental short circuits in the laser diode current circuit.
• Interlock Safety Mechanism: Requires an external hardware switch or key to enable laser operation, adding an extra layer of safety.

Constant Current Source Laser Diode Driver

The LDC series controllers are based on high stability, low-noise current source topology to ensure optimal performance from your laser diode. They provide exceptionally low drift, allowing for consistent and repeatable results. The constant current source topology is based on a precision sense resistor which is placed in series with the laser diode. The voltage across this sense resistor is fed into a differential amplifier, which compares it to the reference voltage. If the measured current deviates from the setpoint, the feedback loop adjusts the control voltage applied to the pass transistor (MOSFET). The transistor acts as a variable resistor, dynamically adjusting to maintain the desired current. The current source automatically adjusts its output voltage to meet the laser's requirements while keeping the current constant.

Integrated TEC Controller

The advanced TEC controller circuit with a full P.I.D. control loop prevents overheating of the laser diode and is designed to reduce thermal fluctuations. Precise thermal stabilization ensures consistent laser output without drift. The TEC control loop provides millidegree temperature stability and can quickly stabilize high heat loads to reduce the risk of damage to your laser. User adjustable upper and lower temperature limits can be programmed to protect the laser diode and the Peltier device. Additionally, TEC output current limits are user-configured to protect the Peltier device from over-drive damage.

Modulation, Internal Function Generator and QCW Modes

In addition to CW (continuous wave) mode of operation, the LDC series laser diode controllers offer flexible modulation capabilities and a built-in QCW function generator. The rear panel of the controller has a BNC input for analog or TTL digital modulation inputs with a 10k Ω input impedance. The controller has an internal function generator which can be used to set the quasi-CW (QCW) pulses. In QCW mode, the user can also set QCW pulses from a remote TTL signal source or by using the internal function generator.

User Interface: Front Panel LCD Display with Keypad | RS232 & USB Interfaces | Analog Signal Controls

These driver & tec controller units offer multiple user interface options. The user has complete control of all laser diode parameters through an intuitive front panel menu. The front panel has an LCD display with a keypad. For remote control, these units come standard with a RS-232 interface and USB adapter. The LabView GUI (included) makes set-up and control of the system fast and simple. An open-source terminal software program is also available for download. The user can also control the unit using analog controls signal inputs available on the rear panel.