News

Welcome to our first Laser Lounge!

Date: Tuesday June 30th
Time: 15.00 CET
Title: Novel narrow linewidth 785 nm diode laser with enhanced spectral purity facilitates low-frequency Raman spectroscopy.

This is a new forum were we like to invite you in for a vitual coffee and sharing insight on lasers from the industry experts.

In this session, we will introduce you to our newest laser for Raman spectroscopy, the 08-NLDM 785 nm ESP. The 785 nm ESP has a patent pending design with enhanced spectral purity making especially suitable for low frequency Raman spectroscopy. We’ll also give you a live demonstration from the lab. Welcome!

Sign up here for our first Laser Lounge webinar

In co-operation with Physics World, HÜBNER Photonics hosted a Webinar June 3rd!

If you missed it, watch it on demand HERE

Our specialists from HÜBNER Photonics will present the characteristics of state-of-the-art tunable CW OPO designs and outline examples of their use in colour center research.

In this webinar you will get a review of state-of-the-art CW OPO technology comprehensible even for the non-specialist, illustrated with recently published real-world experiments.

Widely Tunable lasers in Quantum Research: Novel Lasers for Novel Color Centers

Read more here and watch it on demand

Thanks for being a part of our succesfull webinar yeasterday 
hosted by Physics World!  

Questions are still coming in, and we love it!
Keep sending you questions, we are here for you.

sales@hubner-photonics.com

Read a few of the questions from the webinar:

4. What are the biggest challenges in commerzializing (cw) OPOs?
Answer from J. Sperling: Certainly, one of the biggest challenges is to qualify a suitable pump laser, since our widely tunable lasers require a high-performance continuous-wave and single-longitudinal-mode pump-laser source – like the Cobolt Samba 532 nm 1.5 W which we routinely use for pumping.

5. What about lab requirements and installation of C-WAVE OPO systems by HÜBNER Photonics?
Answer from J. Sperling: To ensure reliable operation within specifications, C-WAVE is to be installed on a vibration-isolated optical table and operated at stable (+/- 2°C) ambient temperature in the range 20-25 °C, at relative humidity in the range 10-85% with a stability better than +/- 10%, and under clear air conditions (free of dust). Installation will be carried out by one of our engineers. We typically schedule one day for installation and one day for in-depth user training on C-WAVE tunable laser Systems

You can also down load the paper from the webinar HERE

Do you want more information and news like this?

International Day of Light: May 16th

This year its also 60 years since we saw the first photons from a laser!

As a laser loving manufacturer we will of course celebrate, even if only virtually with our ‘I love lasers’ video contribution. Watch our submission, meet some of our staff and hear why they love lasers!

This is our submission entry 1

(1 min 11 sec)

Here is our submission entry 2

(1 min 18 sec)

Read more about all the fun activities thats happening all of the world!

The major goals of the International Day of Light are:

• Improve the public understanding of how light and light-based technologies touch the daily lives of everybody and are central to the future development of the global society.
• Build worldwide educational capacity through activities targeted on science for young people, addressing issues of gender balance, and focusing especially on developing countries and emerging economies.
• Highlight and explain the intimate link between light and art and culture, enhancing the role of optical technology to preserve cultural heritage.
• Enhance international cooperation by acting as a central information resource for activities coordinated by learned societies, NGOs, government agencies, educational establishments, industry, and other partners.
• Emphasise the importance of basic research in the fundamental science of light, the need for investment in light-based technology to develop new applications, and the global necessity to promote careers in science and engineering in these fields.
• Promote the importance of lighting technology and the need for access to light and energy infrastructure in sustainable development, and for improving quality of life in the developing world.
• Raise awareness that technologies and design can play an important role in the achievement of greater energy efficiency, by limiting energy waste, and in the reduction of light pollution, which is key to the preservation of dark skyes.

Some history on the laser

May 16 in 1960, Theodore Harold Maiman demonstrated the first fully functional Ruby Laser. Maiman received several highest international awards and was nominated three times for the Nobel Prize. In 2002 Dr. Maiman received an Honorary Doctorate from Simon Fraser University. In 2001 he joined the SFU School of Engineering Science as an Adjunct Professor. Dr. Maiman died in 2007 but his legacy continues growing.

At Cobolt, a part of HÜBNER Photonics, we make high performance diode pumped and diode lasers. After 20 years of making lasers, we still love lasers!

New Conference publication: Pittcon 2020

Lasers for low frequency Raman spectroscopy

Title: Novel narrow linewidth 785 nm diode laser with enhanced spectral purity facilitates low-frequency Raman spectroscopy.

We are happy to be granted permission from Pittcon to share our poster from the 2020 Conference.

Poster: Lasers for low frequency Raman spectroscopy

Abstract
Raman Spectroscopy enables fast, sensitive and label-free chemical analysis of a large range of materials and has become a routine analytical tool in a wide range of material science and process-control applications. As the Raman signal is weak it is critical that the illumination laser has a very high level of spectral purity, for efficient detection of the Raman signal. Most materials can be characterized by studying Raman shifts down to 100 cm-1, but in some cases, for instance for determining the crystallinity of pharmaceutical compounds, it is required to study Raman shifts in the low-frequency regime; <100 cm-1 . 785 nm is the most common illumination wavelength for Raman spectroscopy as it offers the best compromise between Raman signal strength and fluorescence background suppression.

In this paper, we present a novel design for a frequencystabilized 785 nm diode laser using a highly reflective volume Bragg grating (VBG) element that offers not only a narrow spectral linewidth and low wavelength drift, but also a very high level of spectral purity. Using the VBG reflected light as output from the laser suppresses Amplified Spontaneous Emission (ASE) from the diode so that a very high level of sidemode suppression ratio (SMSR) in the laser output is reached within just a few cm-1 away from the main peak without any external spectral filtering. This enhanced spectral purity directly from the laser enables simpler, more compact and more cost-efficient detection of Raman shifts in the very low frequency range.

Lasers for Raman spectroscopy

Authors: Magnus Rådmark, Gunnar Elgcrona, Håkan Karlsson
Part of Pittcon 2020 Proceedings: Vibrational Spectroscopy, 614-15P, (3 March 2020).

New Conference publication: Photonics West LASE 2020

Tunable lasers for quantum technology research

Title: Widely tunable CW Optical Parametric Oscillators: Mastering the challenges posed in quantum technology research

We are happy to be granted permission from SPIE to publish our poster from Photonics West LASE Conference in February 2020.

Poster: Tunable lasers for quantum technology research

Download the poster here

Abstract
Widely tunable continuous wave optical parametric oscillators (cw OPOs) are gaining popularity as novel sources of tunable laser light (C-WAVE tunable laser), not least due to the unprecedented wavelength coverage in the visible and the near infrared spectral range. While the potential and the advantages of tunable cw OPOs are becoming increasingly recognized, in particular within the quantum research community, the experimental requirements are often challenging. In this context, we discuss the characteristics of state-of-the-art tunable cw OPO designs and describe several tuning schemes tailored to meet various experimental needs. In an illustrative fashion, we compare several recently published experimental datasets from photoluminescence excitation experiments, which have been carried out on ensembles as well as on individual quantum emitters under different experimental conditions.

Authors: Korbinian Hens, Jaroslaw Sperling, Niklas Waasem, Ronja Gärtner, Gunnar Elgcrona
Part of SPIE Photonics West. Proceedings Volume 11269, Synthesis and Photonics of Nanoscale Materials XVII; 112690S (2020) https://doi.org/10.1117/12.2545517
Event: SPIE LASE, 2020, San Francisco, California, United States

© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for HÜBNER Photonics website.

Citation Download
Korbinian Hens, Jaroslaw Sperling, Niklas Waasem, Ronja Gärtner, and Gunnar Elgrona “Widely tunable CW optical parametric oscillators: mastering the challenges posed in quantum technology research”, Proc. SPIE 11269, Synthesis and Photonics of Nanoscale Materials XVII, 112690S (2 Feb 2020); https://doi.org/10.1117/12.2545517

New Editorial in Wiley’s Photonics Views Magazine Jan 2020 edition:
Digital holographic microscopy: Requirements of lasers for a novel label-free cytometry tool

by Björn Kemper & Elizabeth Illy

[Extract] Digital holographic microscopy (DHM)[2,3] is an interferometry-based variant of QPI (quantitative phase imaging) in which typically a laser is used as a coherent light source. DHM provides QPI by detecting specimen-induced optical path length changes against the surrounding environment. The specific requirements of the laser depend on the application and the samples under investigation, however the absolutely most important requirement is long coherence length and small footprint. DHM can be modularly integrated into common optical microscopes [3,4]. This allows effortless integration and usage of the technology as a label-free imaging tool in research laboratories.

  Read the whole article for free at Photonics Views

In DHM, reconstruction of digitally captured holograms is performed numerically with a computer. This feature allows imaging of different image planes of a specimen (multifocus imaging) without mechanical focus realignment⁵ and even subsequent autofocusing after capturing of digital holograms is possible. In this way unpredictable focus drifts, e.g., due to environmental condition changes during long-term observations of living cell cultures, or caused by specimen induced movements inside 3D environments such as collagen or gel matrices, can be efficiently corrected. DHM-based QPI moreover allows sophisticated and robust automated object tracking for determination of cell migration and motility and enables in combination with state of the art image processing like segmentation to extract biophysical specimen parameters such as volume, thickness, and dry mass¹. In addition, also optical parameters such as the cellular refractive index, which is related to water content, intracellular solute concentrations, and tissue density^3,6 are accessible from DHM quantitative phase images. These features qualify DHM as a versatile label-free in-vitro imaging tool to analyze tumor, blood, and stem cells in mixtures or composites and allow to study their responses to chemicals or drugs.

Lasers for DHM

The most important performance parameter requirement on a laser for DHM is the coherence length. By coherent this mean that all the light waves travel in synchronization i.e. they have the same period and phase, and this characteristic is found in truly single longitudinal mode (SLM) or single frequency (SF) lasers. The coherence length of a light source is directly correlated to the spectral linewidth of the emitted light (temporal coherence), as well as the homogeneity of the phase front over the beam cross section (spatial coherence). The distance the light needs to be coherent over in order to make an interference pattern is determined by the depth of field; the larger the depth of field the longer the coherence length that is needed. Regularly a coherence length of >1m is more than sufficient. However, typically a larger coherence length allows for more complex and flexible holographic setups.

Besides the coherence length, there are a few other parameters which are important to be considered when selecting a laser for DHM. The wavelength is not so critical so other visible colours, like 561 nm, or near infrared (NIR), e.g., typical Raman wavelengths, could also be used, and may be favorable for specific applications. The main considerations for the wavelength are camera sensitivity (eg CMOS and CCD) and sample properties. For example, short wavelengths in the visible spectrum (VIS) allow QPI with high interferometric sensitivity and latera resolution and are well suited for investigations on thin biological objects such as cells in a Petri dish, while light in the NIR, e.g. 785 nm, is advantageous for imaging thicker samples such as tissue slices. Direct light modulation at up to 10s Hz frequencies, as needed, for example, to minimize the light exposure to living biological specimens during time-lapse investigations, can be achieved with external devices such as AOMs however these add complexity and space, something to be considered when aiming to commercialize the system. A directly modulated compact SLM laser is therefore highly attractive. Since fiber delivery simplifies the design, the beam pointing stability is important to avoid power fluctuations at the sample, as is the beam profile in order to maximise coupling efficiency (Figure 2a).

Fig 2a: Typical beam profile of the SLM 06-DPL used for DHM.

Meet the authors
Björn Kemper, Ph.D., is a senior researcher the Biomedical Technology Center of the Medical Faculty at the University of Münster, Germany. Email: bkemper@uni-muenster.de.

Elizabeth Illy, Ph.D., is the Head of Marketing at HÜBNER Photonics. Email: Elizabeth.illy@coboltlasers.com

References
1. Y.K. Park et al. (2018). Quantitative phase imaging in biomedicine. Nat Photon, Vol. 12, pp. 578-589.
2. B. Kemper and G. von Bally (2008). Digital holographic microscopy for live cell applications and technical inspection. Appl Opt, Vol. 47, pp. A52-A61.
3. B. Kemper et al. (2019). Label-free quantitative in-vitro live cell imaging with digital holographic microscopy. In Bioanalytical Reviews, J. Wegener, Ed. Springer Nature Publishing: Basel, Switzerland.
4. P. Lenz et al. (2016). Multimodal quantitative phase imaging with digital holographic microscopy accurately assesses intestinal inflammation and epithelial wound healing. J Visualized Exp, (115) e54460.
5. P. Langehanenberg et al. (2011). Autofocussing in digital holographic microscopy. 3D Res, Vol. 2, Issue 4.
6. D. Bettenworth et al. (2018). Quantitative phase microscopy for evaluation of intestinal inflammation and wound healing utilizing label-free biophysical markers. Histol Histopathol, Vol. 33, Issue 5, pp. 417-432.
7. L. Kastl et al. (2017). Quantitative phase imaging for cell culture quality control. Cytom A, Vol. 91, Issue 5, pp. 470-481.

Terahertz imagers made easy with T-SENSE
– The innovative post and package scanner for your office

HÜBNER Photonics is proud to announce that the T-SENSE terahertz imager is now available with higher resolution, an increased working distance of 5 cm and a higher workload of 1000 letters/envelopes (DIN C4) per hour.

The improved T-SENSE, which contains leading edge terahertz technology, offers the possibility to help protect staff by visualizing hidden objects and hazardous substances within incoming packages in an efficient and automated way. In addition, due to the insensitivity of living tissue to terahertz waves, these systems do not require the same level of safety precautions compared with conventional devices like x-ray scanners, making the T-SENSE easy to integrate in all security work flows.

The tense worldwide security situation has lead to new ways of ensuring safer and secure workplaces. All work environments receiving letters and parcels are vulnerable to attacks via mail and consequently staff need to be well protected to avoid injury.