Pre-Configured 4-Channel Fiber-Coupled 1310 nm Laser Source

Features

• Independent Temperature Control Gives High Temperature Stability
• Four 1310 nm DFB Laser Output Channels with FC/PC Connectors
• Low Noise Output
• USB Interface
• Low-Profile Package, 2.5" (64 mm) Tall

Thorlabs' Pre-Configured, 4-Channel, Fiber-Coupled Laser Source provides easy coupling and simple control of laser-diode-driven fiber optics. Each system is equipped with four 1310 nm, distributed feedback (DFB) lasers with FC/PC fiber connectors; to discuss custom output connections, contact Tech Sales. These single-frequency laser diodes achieve a 0.1 nm typical linewidth with an excellent side mode suppression ratio (40 dB typical), and provide mode-hop-free, continuous current tuning over the full temperature adjustment range of 20.00 °C to 30.00 °C. The laser source allows more than one channel to be turned on simultaneously; however, it is only possible to adjust the power output of one at a time from the front panel.

Each laser diode is operated from an independent, high-precision, low-noise, constant-current source and temperature control unit. An intuitive LCD interface allows the user to view and set the laser current and temperature independently for each laser. The display indicates the channel number selected, the output wavelength of the source, the operating power calculated from the monitor photodiode, and the actual temperature to which the laser is set.

This device incorporates a microcontroller to fully control the laser's optical power and temperature as well as to monitor the system for fault conditions. The laser source includes a USB connection that allows remote enabling, power adjustment, and temperature adjustment. On the rear panel, analog inputs are available to modulate the laser diodes' outputs with an externally generated waveform. To prevent damage, the microcontroller will disable the output if the sum of the analog input and internal set point exceeds the laser limits. 

Thorlabs offers the MCLS1-CUSTOM as a customizable, 4-channel laser source, with 31 different laser diode options. We also offer the MCLS2-CUSTOM 4-channel, fiber-coupled, customizable source with alternative laser diode and superluminescent diode (SLD) options. The MCLS2-CUSTOM source features a touchscreen interface and a modulation bandwidth of 200 kHz.

Thorlabs also offers other components suitable for the O-band, including our Praseodymium-Doped Fiber Amplifiers (PDFAs) and Booster Optical Amplifiers. Our fiber-coupled LiNbO₃ modulators include FC/PC connectors for easy integration with the MCLS1C1 laser source. For all-in one solutions in high-speed fiber optic test and measurement, we offer reference transmitters, optical transmitter with phase modulators, and calibrated electrical-to-optical converters.

Safety
While the output source for the MCLS1C1 falls within the class 1 laser rating, the system was fully designed to meet laser class 3B requirements. There is an interlock located on the rear panel that must be shorted in order for any laser output to be enabled. This can easily be configured to be triggered by doors to disable the lasers in unsafe conditions. The power switch is a keylock system to prevent accidental or unwanted use. Each source has its own enable button allowing the user to choose the light source or sources he wishes to be active, as well as a master enable that must also be set. Each channel includes a green LED indicator to easily determine its current state. There is a 3 second delay before the lasers turn on, and the user is warned by the LED rapidly blinking. The laser must be turned off before connecting or disconnecting a fiber to the output ports.

In the Box
The MCLS1C1 includes a universal power supply allowing operation over 100 - 240 VAC without the need for selecting the line voltage. The fuse access is conveniently located on the rear panel. This unit is supplied with a region-specific U.S. or standard European line cord, the pre-configured laser source with four 1310 nm DFB lasers installed, the manual, and a USB 2.0 Type-A to Type-B cable.

For in-depth operation instructions, please view the operating manual. A printed copy of this manual is included with each MCLS1C1 Laser Source.

Viewing Information

Thorlabs' Multi-Channel Laser Sources (MCLS1) use a single four quadrant LCD display to access the information for each output channel (see Figure 3.1 for details). Rotate the control knob to the left of the display to scroll through the channels until the desired channel is selected. The control knob is also a select switch that allows access to the laser current and temperature parameters (see below for more information on the display screen in Figure 3.2).

Figure 3.2  LCD Display

• Top Left: Indicates the selected channel.
• Top Right: Indicates the wavelength of the selected channel.
• Bottom Left: Indicates the power level of the laser diode output. If disabled, the power level will read "0.00 mW." If the selected diode does not include a monitor diode, this will read "No PD."
• Bottom Right: Indicates the actual temperature (in °C) that the laser is stabilized to. The default temperature is set to 25.00 °C and is user adjustable. The temperature control is always active and requires 5 to 10 minutes to properly stabilize.

Adjusting the Laser Output Power and Temperature

After selecting a channel, the output power and temperature of the selected laser can be adjusted. The control knob utilizes an intelligent speed control. Turning the knob slowly corresponds to fine adjustment while turning the knob quickly corresponds to coarse adjustment. The laser current adjustment translates to real-time adjustment of output power. The default setting upon first turning on the unit is output power fully off. Note that lasing occurs at the threshold current value, which is different for every source.

Once the desired channel is selected, the Laser Current and Temperature parameters can be adjusted by pressing the control knob in. Pressing in the knob once will select the Laser Current, pressing it a second time will select the Temperature Set Point, and pressing it a third time will revert back to the display mode and lock the selected parameters. The parameter to be adjusted is indicated with blinking text. The resolution is 0.1 mA for the current adjustment and 0.01 °C for the temperature adjustment.

Modulating the Laser Output

The Analog In input can be used to modulate the laser output or to set the laser output remotely using a 5 V power source. The 5 V maximum input corresponds to the maximum calibrated power of each channel. The resulting actual output power is dependent on the set current and operating temperature. In addition, in order to eliminate a dead zone in the power control knob, the output of the unit is offset to the threshold current of the coupled laser diode. Adjusting the knob below threshold will immediately set the current to 0.0 mA (i.e., Standby mode). Therefore, there are two modes of modulation available. Setting the control to "Standby" first allows the analog modulation to utilize the full 0 to 5 V input range. The drawback to this modulation mode is that a minimum voltage is needed to operate above the threshold current. The second mode is to adjust the control knob so that the laser is at or above threshold. The analog modulation voltage will be limited to less than 5 V, but a DC offset will not be required. This DC offset should be kept in mind when using the modulation input since it will limit the actual input voltage range.

Making the Safety Interlock Connections

The MCLS1 series of laser sources are equipped with a remote interlock connector located on the rear panel. All units have this feature regardless of their FDA and IEC classifications. In order to enable the MCLS1 source, a short circuit must be applied across the terminals of the Remote Interlock connector. In practice this connection is made available to allow the user to connect a remote-actuated switch to the connector (i.e., an open door indicator). The switch (which must be normally open) has to be closed in order for the unit to be enabled. Once the switch is in an open state, the MCLS1 source will automatically shut down. If the switch returns to a closed condition, the MCLS1 source must be re-enabled at the unit by pressing the "Master Enable" switch.

Figure 3.4  Interlock Mating Connector