Modulating LED Source for FLIM


Modulated LED Source for FLIM Microscopy

  • For Frequency Domain Fluorescence Lifetime Imaging (FILM)
  • Modulation Frequency: 10 to 100 MHz
  • Optional COllimator Compatible with Olympus, Nikon, Leica, and Zeiss Microscopes


  • Very Stable, Non-Switching, LED Driver
  • Designed for FLIM in the Frequency Domain
  • Compact and Easy to Use
  • Head Mount Compatible with Our SM2 Lens Tubes
  • Optional Adapters for Microscopes:
    Olympus BX and IX, Leica DMI, Nikon Eclipse (Bayonet-Mount),
    Zeiss Axioskop
  • USB 2.0 Interface for Remote Control
  • Compatible with µManager Automation Suite


Thorlabs' DC3100 Series of Modulated LED Sources is designed for frequency domain Fluorescence Lifetime Imaging (FLIM) and other microscopy applications that require advanced modulated high brightness LED sources. This compact LED source is comprised of a high current and high power driver and a LED head with modulating electronics which is designed for high brightness LEDs with high thermal dissipation losses. The LED is included in the head. There are four standard wavelengths available: 365 nm, 405 nm, 470 nm and 630 nm (other wavelengths on request). Collimated Mounting Adapters for the Microscopes Olympus BX and IX, Leica DMI, Nikon Eclipse (Bayonet-Mount) and Zeiss Axioskop are available as optional accessories (see below). The head mount on these LED sources is also compatible with our SM2 (2.035"-40) Lens Tubes.

This LED driver can be remotely operated using the USB 2.0 connector and the included software package with an intuitive GUI and an extensive driver set. The GUI software, µManager, is a versatile, open source, software platform for automated microscopy. A plugin allows the user to control the LED driver right out of the box.

3 Modes of Operation

  1. Internal Modulation:
    Modulated FLIM Mode (Sine Wave), Adjustable LED Brightness, Modulation Frequency in 0.1 MHz Steps and Modulation Depth in Percent
  2. External Control:
    Customizable External Trigger Mode for non FLIM Applications, Adjustable Modulation Frequency up to 100 kHz, Input Voltage 0 to 10 V (1 V corresponds to 100 mA LED Current)
  3. Constant Current:
    For Visual Inspection, Adjustable LED Current: 0 to 1 A in 1 mA Steps

The driver offers three operation modes for great flexibility in usage and applications. The internal modulation mode is the standard mode for typical frequency modulated FLIM applications. Here the LED's modulation frequency can be set from 10 to 100 MHz in 0.1 MHz steps (depending on the connected LED) together with brightness adjustments and setting the percentual modulation depth via the front panel. An additional external trigger mode offers LED control via an external voltage. Here the modulation is adjustable up to 100 kHz by an input voltage of 0 to 10 V (1 V corresponds to 100 mA LED current). This mode is generally used for non FLIM applications.

For easy visual inspection of the microscopy samples the constant current mode allows to control the brightness of the LED by a non modulating LED current from 0 to 1 A.

Microscope Adapters


The COP series adapters are designed to collimate the light emitted by the LED and mate the LED mounting head directly to the illumination ports on Olympus IX/BX (COP1), Leica DMI (COP2), Zeiss Axioskop (COP4), or Nikon Eclipse (COP5) microscopes. These adapters are available with one of two AR coatings: -A for 350 nm - 700 nm, and -B for 650 - 1050 nm.

The rear of the collimator accepts any of the modulated LED sources described above. To switch between LED sources, simply unscrew the LED housing and replace it with an alternative housing.

Additional Wavelengths

If the wavelengths of the standard DC3100 LED head do not match your requirements, we also offer the wavlengths listed in the table below and other custom wavelengths. Please contact your local tech support team for help ordering these specials.

ColorUVUVUVRoyal BlueBlueCyanGreenAmberRedDeep RedIR
365 nm 385 nm 405 nm 455 nm 470 nm 505 nm 530 nm 594 nm 627 nm 660 nm 850 nm

Note: The DC3100 driver sold with the kits on this page is intended only for use with the LEDs also sold on this page. It is not compatible with the other LEDs manufactured or sold by Thorlabs.


Collimation Accessory for Modulated FLIM LEDs

Thorlabs offers collimation adapters with AR-coated aspheric condenser lenses (EFL: 40 mm) for collimating the output from our mounted LEDs. Two AR coating options (-A: 350 - 700 nm and -B: 700 nm - 1050 nm) and four different collimator housings are available; each is designed to mate to the illumination port on a Olympus IX/BX, Leica DMI, Nikon Eclipse, or Zeiss Axioskop microscope.

Collimation Adapter Selection Guide
Compatible Microscopes Olympus BX & IXa Leica DMI Zeiss Axioskop Nikon Eclipse
AR Coating Range of
Condenser Lens
Lens Item # Collimating Adapters for Olympus BX \<br /\>& IX Microscopes Collimating Adapters for Leica DMI Microscopes Collimating Adapters for Zeiss Axioskop Microscopes Collimating Adapters for Nikon Eclipse Ti and Ni-E Microscopes
350 - 700 nm ACL5040-A COP1-A COP2-A COP4-A COP5-A
650 - 1050 nm ACL5040-B COP1-B COP2-B COP4-B COP5-B


Frequency Domain FLIM

FLIM (Fluorescence Lifetime Imaging) is an imaging technology that utilizes the exponential decay rate of the fluorescence from a fluorescent sample. It is mainly used with confocal microscopy and other microscope systems. The image in FLIM is based on the lifetime of the fluorophore signal, rather than its intensity. This minimizes photon scattering in thick layers of the sample.

Modulated Excitation and Fluorescence Signal used in Frequency Domain FLIM

Modulated Excitation and Fluorescence Signal

As an alternative to Time Domain FLIM where the decay time of single excitation pulses is measured in Frequency Domain FLIM the fluorescence lifetimes is determined by phase and amplitude changes of the fluorescence excited by a modulated light source. Here the intensity of the light source is continuously modulated at high frequency. Since the excited state has a lifetime, the fluorescence signal is delayed with respect to the excitation signal plus reduced in amplitude. The lifetime can be determined from this phase shift and the amplitude reduction.


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