Thorlabs MC2000 Optical Chopper System with Interchangeable Chopper Wheels
| Brand | Thorlabs |
|---|---|
| Origin | USA |
| Manufacturer Type | Authorized Distributor |
| Import Status | Imported |
| Model | MC2000 |
| Pricing | Upon Request |
Overview
The Thorlabs MC2000 Optical Chopper System is a precision-engineered, microprocessor-controlled rotating chopper designed for high-stability amplitude modulation of optical beams in demanding scientific and industrial applications. It operates on the principle of mechanical beam interruption via precisely machined, photo-lithographically defined chopper wheels mounted on a low-vibration, rare-earth magnet DC motor. Unlike open-loop speed control systems, the MC2000 employs a crystal-stabilized phase-locked loop (PLL) architecture to maintain exact synchronization between chopping frequency and an external reference signal—enabling sub-degree phase stability and long-term frequency accuracy. This architecture ensures minimal low-frequency drift (<20 ppm/°C) and exceptionally low phase jitter (as low as 0.08° rms typical), critical for pump-probe spectroscopy, lock-in detection, heterodyne interferometry, and other time-resolved optical measurements requiring coherent signal referencing.
Key Features
- Crystal-stabilized PLL motor control for precise frequency and phase locking to external TTL/CMOS reference signals
- Harmonic (2×–15×), subharmonic (1/2×–1/15×), and fractional harmonic generation via on-board microprocessor
- Graphical 240 × 128 pixel LCD display for real-time parameter monitoring and intuitive front-panel operation
- USB 2.0 interface supporting remote computer control, firmware updates, and script-based automation
- Non-volatile memory for storage and recall of multiple user-defined configurations
- Modular chopper wheel design with interchangeable blades covering 1 Hz–10 kHz chopping range
- Stable mechanical platform with 2-inch center-spacing mounting slots (¼”-20 threaded)
- Lemo-style quick-connect cabling for simplified setup and robust electrical connection
Sample Compatibility & Compliance
The MC2000 is compatible with a full suite of Thorlabs chopper wheels—including single-frequency options (MC1F2, MC1F10, MC1F15, MC1F30, MC1F60, MC1F100) and dual-frequency MC2F57 (7 outer / 5 inner slots). While third-party chopper wheels (e.g., from Scitec Instruments) may physically mount, Thorlabs does not guarantee functional compatibility or operational safety due to variations in slot geometry, inertia, and balancing tolerances. The system meets general-purpose laboratory electromagnetic compatibility (EMC) requirements per IEC 61326-1 and is designed for use in environments compliant with ISO/IEC 17025-accredited testing laboratories. Its PLL synchronization capability supports traceable timing alignment with instruments adhering to IEEE 1139 or ANSI/IEEE Std 100-2000 definitions of frequency stability and phase coherence.
Software & Data Management
The MC2000 supports local configuration via its rotary encoder-based front panel interface and remote operation via USB using Thorlabs’ proprietary MC2000 Control Software (Windows-compatible). The software enables scripting (via LabVIEW, Python, or MATLAB APIs), real-time frequency sweep programming, harmonic/subharmonic ratio definition, and automated calibration logging. Firmware updates—distributed through Thorlabs’ official support portal—preserve audit trails and maintain version consistency across multi-instrument setups. All stored configurations include timestamped metadata, supporting GLP-compliant documentation workflows. While the device itself does not implement FDA 21 CFR Part 11 electronic signature controls, its deterministic behavior, non-volatile settings retention, and traceable firmware revision history align with GMP-aligned instrument qualification protocols for regulated R&D environments.
Applications
- Pump-probe ultrafast spectroscopy: independent modulation of pump and probe beams using dual-frequency MC2F57 blade
- Lock-in amplifier referenced measurements: harmonic locking to external oscillator outputs for noise rejection
- Optical nulling and ratiometric photometry: simultaneous dual-frequency modulation for common-mode drift suppression
- Time-resolved fluorescence lifetime imaging (FLIM): gated excitation synchronized to detector readout clocks
- Fourier-transform infrared (FTIR) source modulation: stable chopping for interferometer-based spectral analysis
- Calibration of photodetectors and optical power meters under modulated irradiance conditions
FAQ
What is the minimum and maximum chopping frequency supported by the MC2000?
The usable frequency range depends on the installed chopper wheel: from 1 Hz to 10 kHz, with resolution as fine as 0.01 Hz (for 2-slot blades) or 1 Hz (for all others).
Can the MC2000 synchronize to an external reference signal from a third-party lock-in amplifier?
Yes—the device accepts TTL/CMOS-level reference inputs and supports harmonic, subharmonic, and fractional harmonic locking to external sources including DSP-based lock-in amplifiers.
Is dual-frequency modulation possible with a single chopper wheel?
Yes—the MC2F57 dual-slot wheel provides two independent modulation frequencies (outer 7-slot and inner 5-slot patterns) enabling ratio-metric or differential optical experiments.
Does the MC2000 support firmware updates in the field?
Yes—firmware can be updated via USB using Thorlabs’ official software; the unit must remain powered and idle during the update process.
Are non-Thorlabs chopper wheels supported?
Physical mounting may be possible, but functional compatibility—including phase jitter, frequency stability, and harmonic generation—is not guaranteed and may pose mechanical or electrical risks.
