CW lasers in the visible range are widely used in fluorescence microscopy applications. The fluorescence from specific fluorophores or biomarkers is detected in confocal configurations enabling fast and high spatial resolution imaging of cells, organisms, sub-cellular structures and cell dynamics in live cells.

The resolution of these imaging techniques is fundamentally limited to ~200 nm by the diffraction limit of the laser (the Abbe principle). Over the last decades a number of so called super-resolution imaging techniques have been developed that are capable of going beyond the diffraction limit through manipulation of the fluorescence signal. Examples of super-resolution imaging techniques include STED, STORM, PALM, SIM and RESOLFT. These new techniques have enabled dynamic studies of microbiological structures at molecular level in live cells and have revolutionized the field of light microscopy.

Flow cytometers is a bioanalytical tool in which single or multiple cellular properties are determined by analyzing large populations of cells. In a standard configuration the fluorescence labelled cells pass through the laser beam in a hydro-dynamically focused jet stream in a flow cell.

More advanced systems can be used for Fluorescence-Activated Cell Sorting (FACS). Cytometry instruments are commonly used tools in the fields of hematology and immunology, and are used in biomedical research as well as in clinical diagnostics applications.

All Cobolt lasers offer high power, excellent beam quality and low noise, which are important properties in order to maximize resolution and sensitivity (often referred to in terms of a low CV value) of the instruments, and for applications with high throughput requirements.

Cobolt offers a range of high performance, reliable and user-friendly laser assemblies specifically tailored for advanced Optogenetics research. The laser assemblies have been developed in close collaboration with leading Optogenetics research labs and offer experiment-ready solutions for channelrhodopsin activation and halorhodopsin inhibition.

The Cobolt Optogenetics solutions include single-line lasers with stable and efficient coupling into multi-mode fibers, two lasers on a common platform launched into one common fiber coupler or two lasers sitting side by side launched into one fiber coupler each, suitable for 2-into-1 coupling using e.g. fused fibers. The lasers are available at various wavelengths matching the sensitivity peaks of the most popular Rhodopsins and with output powers >100 mW.

• 473 nm, 532 nm, 561 nm, 594 nm, 638 nm, 660 nm
• >100 mW output power
• Fast and high aspect ratio modulation up to 3 MHz (direct current modulation or integrated AOM)
• Stable and efficient coupling into optical fibers
• Single-line lasers or 2-line combiners

“非弹性散射的光”,或拉曼了ct, was observed in practice for the first time in 1928 by C.V. Raman for which he was awarded the Nobel Prize in 1930. In Raman spectroscopy an incident laser beam (in the UV visible-near IR spectral range) is frequency shifted by this inelastic scattering in the material or substance studied.

频移(斯托克城)转变源于interactions of the laser beam with molecular vibrations, phonons or other excitations in the material and the resulting spectrum provides quantitative and spatial information about the chemical compound distribution in the material. A main advantage of Raman spectroscopy is its capability to offer label-free biochemical and material analysis. The increasing availability of high performance compact DPSS lasers across a broad range of wavelengths from the UV to the NIR has strongly contributed to making Raman microscopes and spectrometers a powerful and increasingly popular analytical tool not only for material science in laboratory environment but also for on-line quality and process control in e.g pharmaceutical and semiconductor and chemical industries.

The Cobolt DPSS lasers on the 04-01, 05-01 and 08-01 platforms are perfectly suited for demanding Raman spectroscopy applications. Stable single-frequency operation combined with the ultra-robust thermo-mechnical architecture of HTCure provides narrow linewidth (<1MHz), extremely low spectral drift (<2 pm over 8 hs) and a spectral purity better than 60 dB, which allows for very high resolution Raman spectroscopy and a possibility to detect low frequency Raman signals even down in the THz regime.

Laser Doppler Velocimetry is a well established method for analysing particle movement at a single point, either in a gas or a liquid.
This information is typically collected using two intersecting collimated laser beams. The beams intersect and interfere in the region for analysis. The particles passing through this region reflect light and from this data it is possible to measure the Doppler shift and therefore velocity of the particles.

lasers for doppler velocimetry using LDVThe laser source suitable for such applications needs to have long coherence length, operate single longitudinal mode, and have good power and noise stability. Cobolt CW DPSS lasers are thus perfectly suited to such an application. In addition, Cobolt’s range of DPSS lasers also includes shorter wavelengths, such as 355nm, that can be used to give additional information about the size of the particles.

In this applications note we read how the flexibility of the C-WAVE’s single frequency tunable wavelength can be utilized for ion trapping experiments.

Coulomb crystals consisting of isotopically pure Magnesium ions are build employing a new tunable continuous-wave (cw) laser light source: Mg atoms are isotope-selective ionized by resonant two-photon excitation at a wavelength of 285.3 nm. The UV laser light is generated via resonant second-harmonic generation of the output of a new cw laser C-WAVE that offers about 0.5 W single frequency output power that is tunable in the range 450 – 650 nm. The created Mg ions are trapped and cooled, building 2D Coulomb crystals which are used for further investigation.

The production of high quality holographic images has always relied on lasers with long coherence length and single mode properties in order to achieve stable interference for the entire exposure time.

Today holograms are not only appreciated as art works but they are also used for improved security measures, for instance on credit cards and bank notes, for real-time sub-micron measurements and for advanced presentation in 3D format.

Cobolt DPSS lasers are a very appropriate laser source for holography due to their extremely narrow linewidth, which translates to a long coherence length, very stable power and single mode properties. Stable single mode operation is particularly important for large area holograms where long exposure times are often required.

HÜBNER Photonics’ single frequency tunable laser, with output in the region 450 nm – 650 nm offers the perfect flexibility to select the exact wavelength for exposures, either as a stand alone laser source or as a 4th laser source in an RGB set-up.

Optical tweezers (originally called “single-beam gradient force trap”) are a bioanalytical instrument that makes use of a highly-focused laser beam to provide an attractive or repulsive force, depending on the refractive index mismatch to physically hold and move microscopic dielectric objects. Optical tweezers have become a well known and successful tool in studying a variety of biological systems.
The narrowest point of the focused beam, known as the beam waist, contains a very strong electric field gradient. It turns out that dielectric particles are attracted along the gradient to the region of strongest electric field, which is the center of the beam. The laser light also tends to apply a force on particles in the beam along the direction of beam propagation. By utilising this force it is possible to manipulate biological cells and even move them from one position to another.

A basic optical tweezer setup includes:
a laser, a beam expander, some optics used to steer the beam location in the sample plane, a microscope objective and condenser to create the trap in the sample plane, a position detector (e.g. quadrant photodiode) to measure bea m displacements an d a microscope illumination source coupled to a CCD camera (see Fig.1 on the right). All Cobolt DPSS lasers offer excellent beam quality and very low noise, which are extremely important properties of lasers used for optical tweezers

Plasmon Focusing on Single Crystalline Gold Platelets

In this applications note we read how the flexibility of the C-WAVE’s single frequency tunable wavelength can be utilized in nanophotonics experiments.

高度本地化的操纵fi古人的苏rface plasmon polaritons (SPPs) forms the backbone for a vast fi eld of applications. We investigate the SPPs excited on a single crystalline gold nanoplatelet milled with a plasmonic lens structure using a scattering type scanning near fi eld optical microscope. SPPs are excited at different wavelengths in the visible regime employing a new tunable continuous wave source. Wave vector selection of the SPPs by the gold structures corresponded well with the numerically calculated dispersion relationship.’

Single Molecule Spectroscopy using C-WAVE

In this applications note we read how the flexibility of the C-WAVE’s single frequency tunable wavelength can be utilized for single molecule spectroscopy experiments.

The fluorescence excitation spectra of single organic molecules in a solid state crystal are measured at cryogenic temperatures. As a tunable laser light source, the optical parametric oscillator C-WAVE is employed. C-WAVE exhibits promising features as a laser light source for spectroscopy applications, like a broad tuning range from 450 to 650 nm, a narrow linewidth < 1 MHz, and mode-hopfree tuning over > 25 GHz. This report presents the experimental setup and measured spectra, and it discusses the applicability of C-WAVE for high-resolution spectroscopy.