We present a compact and portable stimulated Raman scattering (SRS) imaging system capable of high speed, label-free imaging of cells and tissues. Our setup rapidly acquires multispectral datasets with high chemical specificity by scanning the spectral range of 700-3100 1/cm in just 100 ms, providing a tenfold increase in acquisition speed. It allowed to visualize cell nucleus and cytoplasm changes during drug induced cancer cell death. SRS offers distinct advantages, providing valuable insights into drug-cell interactions, cell morphology, and chemical changes without the interference of exogenous labels. The novel high-speed SRS systems allows rapid screening of drug effects on cancer cells.
We present a fully integrated, clinical-compatible SRS imaging device giving access to the complete Raman spectrum during tumor surgeries. Leveraging the advantages of a compact and robust fiber laser, we have integrated the entire microscopy system into a clinical cart, facilitating deployment in diverse clinical environments. The laser provides rapid tunability within milliseconds across a broad spectral range of 700 to 3300 cm^-1, covering biomedically relevant resonances in the fingerprint region. For detailed examination of larger tissue samples, we have designed a high-speed, low-resolution imaging mode to quickly identify cancerous hot-spots, followed by a high-resolution imaging mode.
We present a turn-key portable picosecond fiber laser for efficient quantum dot excitation to generate single photons. The laser combines a mode-hop-free tunability in the regions 770-980 nm and 1150-1500 nm with a high pulse-to-pulse coherence of 98%. A high single photon purity and indistinguishability were demonstrated. An excellent long-term power stability with a standard deviation of less than 0.3% and wavelength stability of better than 5 pm were achieved. The laser enables excitation of different semiconductor quantum dots and excitation schemes, essential for versatile easy-to-use single-photon sources based on quantum dots for research applications and commercial quantum computing.
We present a turn-key portable picosecond fiber laser for efficient quantum dot excitation to generate single photons. The laser combines a mode-hop-free tunability in the regions 770-980 nm and 1150-1500 nm with a high pulse-to-pulse coherence of 98%. A high single photon purity and indistinguishability were demonstrated. An excellent long-term power stability with a standard deviation of less than 0.3% and wavelength stability of better than 5 pm were achieved. The laser enables excitation of different semiconductor quantum dots and excitation schemes, essential for versatile easy-to-use single-photon sources based on quantum dots for research applications and commercial quantum computing.
Hyperspectral Stimulated Raman Imaging (SRS) has shown great promise as a label-free chemical imaging technique in biomedical and medical research. We present recent developments in SRS integrating a compact and portable all-fiber laser with balanced detection into an imaging system, aiming to enhance ease-of-use, specificity, and reliability in acquiring high-speed, multicolor chemical images. The system's adaptability is highlighted by integrating the entire microscopy system into a clinical cart, ensuring clinical compatibility as well as its seamless integration with a Nikon Eclipse Ti widefield microscope, providing a compact and robust extension for varied imaging setups. The system incorporates a balanced detector to enable shot-noise-limited measurements, accommodating over 100mW of Stokes power on the detector.
We present a fully integrated, clinical-compatible SRS imaging device giving access to the complete Raman spectrum during tumor surgeries. Leveraging the advantages of a compact and robust fiber laser, we have integrated the entire microscopy system into a clinical cart, facilitating deployment in diverse clinical environments. The laser provides rapid tunability within milliseconds across a broad spectral range of 700 to 3300 cm^-1, covering biomedically relevant resonances in the fingerprint region. For detailed examination of larger tissue samples, we have designed a high-speed, low-resolution imaging mode to quickly identify cancerous hot-spots, followed by a high-resolution imaging mode.
Hyperspectral Stimulated Raman Imaging (SRS) has shown great promise as a label-free chemical imaging technique in biomedical and medical research. We present recent developments in SRS integrating a compact and portable all-fiber laser with balanced detection into an imaging system, aiming to enhance ease-of-use, specificity, and reliability in acquiring high-speed, multicolor chemical images. The system's adaptability is highlighted by its seamless integration with a Nikon Eclipse Ti widefield microscope, providing a compact and robust extension for varied imaging setups. The system incorporates a balanced detector to enable shot-noise-limited measurements, accommodating over 100mW of Stokes power on the detector.
We present a fully integrated, clinical-compatible SRS imaging device giving access to the complete Raman spectrum during tumor surgeries. For detailed examination of larger tissue samples, we have designed a high-speed, low-resolution imaging mode to quickly identify cancerous hot-spots, followed by a high-resolution imaging mode. Leveraging the advantages of a compact and robust fiber laser, we have integrated the entire microscopy system into a clinical cart, facilitating deployment in diverse clinical environments. The laser provides rapid tunability within milliseconds across a broad spectral range of 700 to 3300 1/cm, covering biomedically relevant resonances in the fingerprint region.
We present a fully integrated, clinical-compatible SRS imaging device giving access to the complete Raman spectrum during tumor surgeries. Leveraging the advantages of a compact and robust fiber laser, we have integrated the entire microscopy system into a clinical cart, facilitating deployment in diverse clinical environments. The laser provides rapid tunability within milliseconds across a broad spectral range of 700 to 3300 cm^-1, covering biomedically relevant resonances in the fingerprint region. For detailed examination of larger tissue samples, we have designed a high-speed, low-resolution imaging mode to quickly identify cancerous hot-spots, followed by a high-resolution imaging mode.
We present our recent developments in utilizing a compact and portable light source for high-speed multicolor stimulated Raman scattering imaging (SRS) in biomedical and medical environments. The source combines a rapid and wide tunability for accessing Raman bands between 700 and 3300 cm-1 with high stability in terms of power (deviation < 0.3 %) and wavelength (deviation < 0.5 pm) over more than 100 h. We were able to shorten the Stokes pulse duration to below 3ps, resulting in a twofold increase in SRS signal intensity compared to our previous version (7ps).
We present our recent developments in utilizing a compact and portable light source for high-speed multicolor stimulated Raman scattering imaging (SRS) in biomedical and medical environments. The source combines a rapid and wide tunability for accessing Raman bands between 700 and 3300 cm-1 with high stability in terms of power (deviation < 0.3 %) and wavelength (deviation < 0.5 pm) over more than 100 h. We were able to shorten the Stokes pulse duration to below 3ps, resulting in a twofold increase in SRS signal intensity compared to our previous version (7ps).
We present a novel turn-key portable fiber laser for efficient quantum dot excitation to generate single photons. The laser combines a mode-hop-free and alignment-free tunability between 770 nm to 980 nm with a high pulse-to-pulse coherence of 98%. Second order correlation measurements demonstrate a high single photon purity. The laser shows long-term power stability with a standard deviation of less than 0.3% and wavelength stability of better than 5 pm. This development constitutes an essential step for advancing single-photon sources based on quantum dots in terms of integrability and ease of use for research applications and commercial quantum computing.
We present our recent developments in utilizing a compact and portable light source for high-speed multicolor stimulated Raman scattering imaging (SRS) in biomedical and medical environments. The source combines a rapid and wide tunability for accessing Raman bands between 700 and 3300 cm-1 with high stability in terms of power (deviation < 0.3 %) and wavelength (deviation < 0.5 pm) over more than 100 h. We highlight applications in metabolic cell imaging and the identification of pharmaceuticals in complex environments such as skin by harvesting contrast from several Raman bands.
We present recent developments on our portable light source for multicolor coherent Raman imaging. The source combines a rapid and wide tunability for accessing Raman bands between 700 and 3200 cm-1 with high stability for long term measurements utilizing software PID-stabilization by means of an integrated optical miniature spectrometer. We present a long-term power stability with a standard deviation of less than 0.3% and a wavelength stability of better than 5pm over the course of 100h. This development constitutes an important step for advancing CRI microscopy in terms of portability and stability for applications in medical diagnostics or environmental sensing.
We present high-speed multicolor stimulated Raman scattering imaging (SRS) enabled by an all-fiber light source. With a relative intensity noise level of -157 dBc above 10 MHz the light source is shot-noise limited up to a detector current of 0.75 mA. Compared to other fiber-based light sources optimized for SRS, the presented system is tunable in under 5 ms per arbitrary step between 700 and 3530 wavenumbers. The compact and environmentally stable system is predestined for fast multicolor assessments of medical or rapidly evolving samples with high chemical specificity.
We present multicolor coherent Raman imaging (CRI) with two orders of magnitude enhanced sensitivity accomplished by a frequency modulation (FM) at 20 MHz of a portable fiber optical parametric oscillator (FOPO). The FM is combined with a rapid and wide tunability for accessing Raman bands between 700 and 3500 1/cm within only 5 ms. This development constitutes an important step for advancing CRI microscopy in terms of portability and sensitivity for applications in medical diagnostics or environmental sensing.
We present coherent anti-Stokes Raman (CARS) imaging with our robust all-fiber optical parametric oscillator (FOPO) that is tunable across the whole bio-relevant spectral region (700 to 3530 wavenumbers) in less than 5 ms. The all-fiber operation allows to operate the FOPO on a regular laboratory cart, maximize temporal pulse overlap by dispersion management and inherently minimize beam-pointing. We present first CARS images of DMSO-d6 infiltration into mouse skin imaged in the silent as well as CH-stretch region without any alignment other than electronically tuning the wavelength. The FOPO is ideally suited for label-free, hyperspectral imaging, e.g., in translational research.
We present a rugged all-fiber optical parametric oscillator (FOPO) for coherent Raman imaging (CRI). The FOPO shows ideal performance for hyperspectral video-rate coherent Raman imaging with pulse durations of 7 ps at 40 MHz and switching times of less than 5 ms from 700 to 3530 wavenumbers. Due to our patented all-fiber setup the FOPO runs on a regular laboratory cart. We present shock measurements that resemble typical situations in a clinical environment as well as long-term stability measurements. The presented robust fiber laser system is ideally suited to allow easy access to hyperspectral, high-speed CRI for translational research.
We present high-speed multicolor coherent Raman imaging enabled by a novel all-fiber light source. A high tuning speed of < 5 ms per arbitrary wavelength step (700 - 3530 wavenumbers) allows to switch the wavelength in a frame-by-frame manner when imaging with up to 100 frames/s. The pump (up to 200 mW) and Stokes pulses (> 400 mW) exhibit equal durations of 7 ps. The compact and environmentally stable system is predestined for fast multicolor assessments of medical or rapidly evolving samples with high chemical specificity.
We present high-speed multicolor coherent Raman imaging (CRI) with rapid wavelength tuning within only 5 ms between successive images, enabled by a novel fiber optical parametric oscillator (FOPO). In CRI the limited tuning speed of conventional laser systems (at least several seconds per wavelength change) hinders the rapid acquisition of successive images at multiple vibrational frequencies and is a bottleneck for fast assessments of medical specimens or rapidly evolving samples.
The output pulses of the presented FOPO are tunable across the vibrational spectrum between 865 and 3550 wavenumbers within only 5 ms. Therewith, the wavelength can be tuned in a frame-by-frame manner adequate for an image acquisition with up to 200 frames/s. Tuning of the FOPO is achieved by synchronized changes of both wavelength and repetition rate of the pump pulses, allowed by a novel fiber-integrated pump laser working without a mechanical delay. Based on this tuning mechanism, the FOPO resonator can be composed of all-spliced fiber components. Compared to previously presented FOPOs, the system exhibits short pulse durations of 7 ps and operates at a high repetition rate of 40 MHz to allow short pixel dwell times as low as 25 ns. The pump (<500 mW) and FOPO pulses (up to 200mW) exhibit equal durations and bandwidths below 12/cm. In comparison to previous approaches on multicolor CRI with multiple oscillators, requiring complex setups for synchronization, parallel laser amplifiers with limited emission bandwidth, or fragile mechanical delay lines, the realized FOPO system will dramatically simplify and improve CRI setups.
We present a femtosecond fiber-based optical parametric oscillator (FOPO) for multiphoton microscopy with wavelength tuning by electronic repetition rate tuning in combination with a dispersive filter in the FOPO cavity. The all-spliced, all-fiber FOPO cavity is based on polarization-maintaining fibers and a broadband output coupler, allowing to get access to the resonant signal pulses as well as the idler pulses simultaneously.
The system was pumped by a gain-switched fiber-coupled laser diode emitting pulses at a central wavelength of 1030 nm and an electronically tunable repetition frequency of about 2 MHz. The pump pulses were amplified in an Ytterbium fiber amplifier system with a pulse duration after amplification of 13 ps. Tuning of the idler (1140 nm - 1300 nm) and signal wavelengths (850 nm - 940 nm) was achieved by changing the repetition frequency of the pump laser by about 4 kHz. The generated signal pulses reached a pulse energy of up to 9.2 nJ at 920 nm and were spectrally broadened to about 6 nm in the FOPO by a combination of self-phase and cross-phase modulation. We showed external compression of the idler pulses at 920 nm to about 430 fs and appleid them to two-photon excitation microscopy with green fluorescent dyes.
The presented system constitutes an important step towards a fully fiber-integrated all-electronically tunable and, thereby, programmable light source and already embodies a versatile and flexible light source for applications, e.g., for smart microscopy.
A concept to adjust the output spectral bandwidth of a wavelength-tunable fiber optical parametric oscillator (FOPO) is presented. By adjusting the chirp of the pump pulses relative to the chirp of the resonant pulses, the energy of the output pulses can be reorganized into a wide or narrow spectral bandwidth. We present numerical simulations of a FOPO, which is able to generate pulses with an adjustable bandwidth between 12 and 0.8 nm. Such a FOPO should allow the cost-efficient application within two-photon excited fluorescence microscopy, which benefits from high peak powers, combined with coherent Raman microscopy, which requires spectrally narrow pulses.
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