Optical Frequency Comb

FC1500 ULNplus02 3w


Advanced Features and Benefits

      • Comb Spacing 250 MHz
      • Accuracy 1 x 10-18 (τ >100 s)
      • Stability: 5 x 10-18 in 1 s, 5 x 10-19 in 1000 s
      • Operational Range from 500 nm to 2 μm
      • Integrated Phase Noise <80 mrad [1Hz - 2 MHz]
      • High Repetition Rate
      • High Bandwidth >1 MHz Actuators for CEO and Repetition Rate
      • Fully Fiber-coupled CEO Frequency Generation
      • Turnkey Metrology System. Fully automated, including data evaluation software, designed for continuous operation
Comb Spacing 250 MHz
Accuracy 1 x 10-18 for τ > 100s*
Stability 5 x 10-18 in 1s*, 5 x 10-19 in 1000 s*
Integrated Phase Noise <80 mrad [1Hz - 2 MHz]
Line Width <1Hz*
Tuning Range of Comb Spacing >4 MHz
Tuning Range of CEO Frequency >250 MHz
Laser Outputs  five fiber-coupled, linearly polarized, PM output ports
Center Wavelength 1560 nm
Spectral Range >25 nm (500-1050 nm with M-VIS,1050-2100 nm with M-NIR)
Average Output Power >10 mW from each laser port (>100 mW with M-VIS, >200 mW with M-NIR)

spectral purity transfer between fundamental and a user-defined wavelength in the 500-2100 nm range

*phase lock to optical reference

modified Allan deviation ( λ -type counter, timebase 1ms)

limited by resolution bandwidth of analyzer



The FC1500-ULNplus Ultra Low Noise Optical Frequency Comb brings the system performance to the next level. Additional hardware, optimized components and engineering ingenuity resulted in a perfect flywheel for transferring frequency stability between two or more user-defined frequencies at the 10−19 level. This exceeds the stability of any optical oscillator demonstrated to date, and transcends the stability requirement for optical clocks.

The ability to measure sub-10−18 level frequency shifts can be relevant for applications such as optical clocks in quantum sensing and fundamental physics. Our all polarization maintaining figure 9® mode locking technology together with high bandwidth actuators (>1 MHz) for both the carrier-envelope offset frequency and the repetition rate guarantee ultimate performance.

The performance is proven in an out of loop comparison between two independent ULNplus optical frequency combs, which is integral part of the quality check during factory acceptance of each system. Thus Menlo guarantees and proves by measurement that the outstanding spectral purity of the oscillator is transferred perfectly to the desired wavelength for every system delivered.


  • M-Mid-IR Extension Package

    Product Code: M-Mid-IR

    Extends the stabilized comb spectrum to 3.3µm with more than 200nm spectral width and > 120 mW average power via a free-space output port.

  • M-NIR Extension Package

    Product Code: M-NIR

    Extends the stabilized comb spectrum to a range of 1050 - 2100 nm with free-space output port and >200 mW average power. The measurement port can be optimized independently from the CEO frequency stabilization.

  • M-VIS Extension Package

    Product Code: M-VIS

    Extends the stabilized comb spectrum to the 500-1050 nm range with free-space output port and >100 mW average power.

  • HMP High Power Measuring Port

    Product Code: HMP

    Provides stabilized comb light with highest power at customer-defined wavelengths for high precision measurement of lasers with low power levels (<100 µW). A minimum of 3 mW average power in a 3 nm window is provided at the central wavelength specified by customer. Available for 1050 - 2100 nm (HMP-NIR), or 525 - 1050 nm (HMP-VIS). The output is fiber coupled and optional available as free space.

    For 390 - 400 nm (HMP-UV) a minimum of 1 mW average power in a 1 nm window is provided. the output is free space.

  • P250 PM PULSE EDFA Erbium-doped Fiber Amplifier

    Product Code: P250 PM PULSE EDFA

    All polarization maintaining (PM) amplifier delivers intense near infrared pulses with >350 mW at 1560 nm. Several amplifiers can be added for multiple measurement ports.

  • M-780 High Power Measuring Port at 780 nm

    Product Code: M-780

    Output provides stabilized comb light with highest power at 780 nm.
    Contains an amplifier and subsequent frequency conversion, delivering a minimum of 150 mW average power with a central wavalength in the range of 780-800 nm. The output is free space and optional available as fiber-coupled.

  • BDU Beat Detection Unit

    Product Code: BDU

    Generates and measures the beat signal between the frequency comb and an external continuous wave (cw) laser. Available for various spectral ranges, with free space or fiber-coupled optics, and matched to the customer's laser.

    For more information: BDU

  • LLE-SYNCRO Laser Locking Electronics

    Product Code: LLE-SYNCRO

    Allows locking of an external cw laser to the stabilized frequency comb. Performance has been field tested with lasers from major suppliers.

    For more information: LLE-SYNCRO

  • Microwave Ultrastable RF Output

    Product Code: Microwave

    Ultrastable RF output in the 1 MHz-10 GHz range. Utilizing a high-sensitive fast photodetector and a frequency divider where needed.

  • ORS Optical Reference System

    Product Code: ORS

    The ORS Optical Reference System consist of a CW laser locked to a stable high-finesse optical reference cavity made of ultra-low expansion (ULE) glass. It offers ultra-narrow linewidth (< 1Hz) and outstanding short time stability (<2 x 10-15) at wavelengths such as 657 nm, 689 nm, 698 nm, 729 nm, and many others from 500 nm to 1600 nm. By locking the FC1500-250-ULN to the ORS, the purity of this state-of-the-art optical reference can be transferred throughout the entire frequency comb spectrum.

    For more information: ORS

Analysis of the out of loop beat signal between two ULNplus combs at the Strontium clock transition frequency: The extremely low phase noise proves that the spectral purity is transfered to the target wavelength, which makes the ULNplus a unique clockwork for Strontium and other optical lattice clocks.

PN integratedPN CC 1Hz 1MHz 01


Application Notes

Menlo Expert Ben Sprenger 2019
Dr. Benjamin Sprenger
Your direct line to our expert

Data sheets

Product literature

Ordering information

  • Product Code
  • FC1500-ULNplus

+49 89 189166 0

Menlo Systems, Inc.
+1 973 300 4490

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