SMC11 Puy Mary – Ultra Low Noise Current Source


  • 210mA or 470mA source
  • Ultra-low current noise
    • density  ≤ 15 pA/√Hz
    • RMS  ≤ 25 nA
  • Adjustable current limiter
  • Fast servo modulation input (30 MHz)
  • RF modulation input
  • Slow turn-on
  • Analog design – Free of digital noise
  • EMI noise immunity
  • High reliability
  • Ideal for RIO Planex™, DFB and VCSEL lasers.
  • 3D models

Noise Performance

Noise performance comparisons between the SMC11 and some “low-noise” competitors.

Transfer Function


  • For use with grounded anode laser (telecom diodes)
  • Laser frequency stabilization
  • Opto-electronic oscillator (OEO)
  • Optical Phase-locked loop (OPLL)
  • LIDAR applications
  • Photonics
  • Atomic Physics
  • Ideal for RIO Planex™ Lasers


The SMC-Series modules are the ideal instruments for controlling the current and the temperature of narrow linewidth laser diodes. With an ultra-low noise current sink (SMC11) and sub-mK thermal control stability (SMC20 & SMC31), the SMC-Series is the right choice for the most demanding applications. Because SMC-Series was first designed for frequency stabilization and OPLL applications, the SMC11 current sink also provides two current modulation inputs since ultra-low noise current and fast current modulation are key parameters for achieving the best phase noise performance of your stabilized lasers. Using the SMC-Series laser diode controller with the SMA– or SMB-Series modules, complete turn-key solutions are available for your laser frequency stabilizations or phase-locked lasers.

Related Modules

The SMC11 is the current source module of our SMC-Series modules. It is intended for anode-grounded [1,4] lasers diodes (e.g. most of telecom devices). Because the SMC11 is a minimalistic [5] module designed to be used in different situations [2], some external control signals are necessary to operate the current source. For this purpose, 2 optional modules – SMC111 and SMC121 – are provided to manually access and control these I/O signals. The SMC111 module is a 11-toggle switch interface used to control the status of one SMC11 current source and one thermal stabilization (SMC20 & SMC31 modules) while the SMC121 BNC interface module allows the user to access the I/O signals of the current source (Interlock, Current Monitor, Remote Control etc).

Since noise is a primary concern, the SMC11 current source does not include any power supply generator on its board. The required DC power supply voltages (+/-15V and +5V) must be fed to the current source through its stacking connectors. The SMZ00 power interface module has been designed to provide a safe and reliable way to connect the power supplies to the stacked modules. It features both reverse voltages protections and surge currents limitations. In addition, the SMZ00 module includes passive filter stages to remove the conducted noise from power supply sources. The SMZ00 power interface module is connected to the power sources via a 10-conductor cable.

The laser diode is connected to the SMC11 current controller using an SMA coaxial connector located on its front panel. This connection provides the users a convenient way to apply an RF-current modulation without any external bias-tee. Nevertheless, some users just want to replace their noisy current controller with our ultra low-noise source without changing the laser connections. For this purpose, the optional SMC051 module has been designed : it provides both female DSUB9 and DSUB15 connectors to connect the laser using the ILX™ industry standard’s wiring scheme [3].

The laser can be also connected to the SMC11 Current Source without any cables. Indeed, the SMC41 Valescure  is a laser mount module dedicated to telecom laser packaged in butterfly 14-pin cases. With the SMC41 no cable are required to connect the laser to its curent source since the module is connected to the source via the stacking connectors. RF modulation is still preserved.

All these modules are optional but they are recommended since you will have to make your own assembly otherwise. The optional modules can be ordered grouped or separately. Some R&D customers just buy the SMC11 current source and use the board as a sub-system in their designs.

Note that ready-to-use current controllers are provided by the SR300-Series solutions.

Mounting the Current Source Module

To increase their flexibility, all SM-Series modules are designed to be assembled in standard cases (19″ or less) and as sub-systems. For a standard 3U (128.4mm height) case assembly, the modules can be ordered with their front panels, which fix the modules to the case.

For ultimate performance, we also provide shielded desktop cases and low-noise power supplies. Since our SM-Series modules are rack compatible, you can also mount these instruments in any 3U-case of your choice.

You can see how the SMC-Series looks like without any case (see picture in Included Hardware Section). Here, the user is free to mount the stacked modules in his own standard 3U-height case and connect the power supply using the power cable (not shown on the picture). Note that no expensive mother board is required to assemble the modules since they have their own stacking connectors. It is possible to assemble more than one diode laser electronics in full-width 84HP (19″) 3U-height case. Hence, 2 complete diode drivers can be mounted but additional modules from other series (laser stabilization for example) can be also accommodated together. Using a 3U/84HP (19″) case also provides the user to mount his own sub-systems in a same case.

Power requirements

Regarding the power supplies, we can provide low-noise power supplies [6] but, due to the efficiency of our modules, any good laboratory power supply (+/-15V & +5V) will be perfectly adapted, the noise increase should be marginal.

Ready-to-Use Current Sources

The SR300 shows a typical configuration where a standard 3U/42HP (half-19″ width) desktop case accommodates modules of the SMC-Series (the temperature controller modules are also visible on this picture). This case requires DC power supply inputs (+/-15V and +5V), which can be provided by any low-noise power supply or by the SR100 power supply [6].

  • [1] Of course, laser diodes with floating terminals can be also controlled.
  • [2] The SMC11 can be used as a sub-system in a customer specific design.
  • [3] The DSUB9 connector is connected to the SMC11 current source and the optional thermal stabilization modules (SMC20 & SMC31) are connected to the DSUB15.
  • [4] Contact us for any questions regarding the compatibility.
  • [5] A block-diagram can be downloaded from the web page (see Download Section).
  • [6] This power source was first designed to provide low-noise environment for our products.

Examples of compatible Laser Diodes

Non-exhaustive list, contact us for specific information.

Additional Views

The SMC11 Puy Mary Current Source module (front panel not shown).