Monochromator.us

Let there be light! Fiat lux!

Plasma science assessment

The US National Academies has recently started the Decadal Assessment of Plasma Science. The committee invites the US and international plasma science and technology communities to submit white papers addressing accomplishments, science challenges, societal benefit, and interdisciplinary collaborations in plasma science and technology. Instructions for submitting at the bottom of http://nas.edu/plasma. Due February 15, 2019


APS March Meeting

Visit booth #239 at APS March Meeting in Boston 2019 March Meeting

The American Physical Society will hold its 2019 March Meeting and exhibition March 4 through 8, 2019 at the Boston Convention and Exhibition Center in Boston, Massachusetts, USA. APS expects more than 11,000 of the top scientists involved in physics research and applied physics throughout the world to attend. The March Meeting provides an opportunity for one-to-one meetings with vendors and scientists from around the world. Visit McPHERSON at BOOTH #239 when the APS March Meeting comes to town

McPherson's' spectroscopy systems provide flexibility. Users can determine the wavelength range and resolution requirement and then move easily to sampling optics for measurements in the lab or field. With our diverse spectrometers, light sources, and accessories, we can help you to create an optimized system.


Deep- and VUV Absorbance

Absorbance is among the most widely used spectroscopic techniques for studying liquids and gases. It is simple, accurate, and usually easy to do. An absorbance spectrum can be used as a qualitative tool to “fingerprint” substances, or as a quantitative tool to measure concentration, for example. We’ve taken the sensitivity and selectivity of absorbance to the next level with deep UV tools free from interference.

Absorbance measurements take many forms. They work well for gases and liquids, and have found their way into many applications. Samples do not need to fit 1 cm path length cuvettes! Flow cells, dip probes, multi-pass cells, and more, allow sampling to be customized. For example, McPherson has special flow cells for gas and liquid analysis at very short wavelengths. Our absorbance instruments work from 115 or 120 nanometers in the deep UV and up to the Visible light region.

acetone absorbance measured in the deep UV spectroscopy system layout for deep UV and VUV spectral absorbance measurement

McPherson's' spectroscopy systems provide flexibility. Users can determine the wavelength range and resolution requirement and then move easily to sampling optics for measurements in the lab or field. With our diverse spectrometers, light sources, and accessories, we can help you to create an optimized system.


Cleaning diffraction gratings!?

We measured efficiency of a UV ozone-scrubbed and plasma (nitrogen) cleaned replicated diffraction grating. For the test part, reflected diffraction efficiency measurements improve with each cleaning, overall 12% improvement on average. Scanning electron microscope (SEM) images of the optical surface do not indicate structural change or damage.

Despite the title of this post DO NOT ATTEMPT TO CLEAN YOUR DIFFRACTION GRATING! We're reporting work done under controlled circumstances with the VUVAS vacuum UV analytical spectrophotometer that measures transmission, goniometric reflection and diffraction efficiency. It works to wavelengths short as 120 nanometers using vacuum or inert gas (nitrogen) purge. For best stability, we work with nitrogen purge. For windows and other samples, we've also been UV scrubbing and plasma cleaning for better measured results. The cleaning techniques combined with strict operating procedures provide opportunity to measure the real surface – not one changed by exposure to ambient humidity or other factors. Cleaning techniques have become very important in the deep UV, where results are usually improved.

measured diffraction grating efficiency

With UV ozone-scrub and plasma cleaning together or separately, measured diffraction efficiency improved. Approximately 12% improvement was measured, across the board, after the cleaning sequence. Scanning electron microscope (SEM) images from a Phenomm Pure show no change to groove profile or surface of the diffraction grating.

We do not recommend or normally attempt to plasma clean reflective optics. At this time, this series of tests is an exception. In the plasma cleaner, we’ve frequently seen coated surfaces behave like a dielectric and create an arc or discharge causing damage to coatings. During this series of tests and cleaning-cycles, no arcing occurred.


XUV monochromator works 3 different ways

Soft x-ray (SXR) and extreme ultraviolet (EUV) monochromator for analysis and diagnostics with short wavelength / high energy spectra? The vacuum ultraviolet (VUV) Model 248/310 grazing incidence monochromator can do it! Easily make spectral measurements around 13 nanometers and throughout the extreme vacuum ultraviolet and soft x-ray wavelength region. It is ideal for work from 10eV to more than 1000eV. (less than 1 nanometer to more than 300 nanometers overall)

For direct detection of extreme vacuum ultraviolet and soft x-ray wavelengths, windowless back illuminated CCD's are used. Sensitivity of CCD's at short wavelengths can surpass that in the visible spectral region. When gated detection is required, open microchannel plate intensifiers are available. It also works with point detectors and as a scanning monochromator. The slit or detectors scan along the Rowland circle. Integrate with an electron impact or hollow cathode spectral lamp to make a tunable light source.

grazing incidence XUV monochromator

The McPherson Model 248/310 is perfect for XUV HHG spectroscopy applications. X-ray plasma diagnostics, extreme ultraviolet optical characterization, soft x-ray metrology and astrophysics calibration are typical applications. Attosecond pulse, high harmonic lasers (HHG), and EUVL semiconductor source and process development are too. For all, the McPherson Model 248/310 spectrometer provides user-friendly and fast spectra from a wide range of extreme vacuum ultraviolet (VUV) and soft x-ray (SXR) wavelengths.


Color of the stars

Love this cool sequence of photos of Sirius, the Dog Star. I think we're seeing atmospheric chromatic aberration or atmospheric refraction that makes the apperance of Sirius change (it is not literally changing colors). The photo was found online at earthsky.org. Photo was taken by Amanda Cross in Euxton, Lancaster, UK who said This is the star Sirius early in the morning. I used a high ISO and 1/320 shutter speed. The colour flashes are picked up by the camera as the atmosphere splits the light from the star. No color enhancements were made to this image. This is how the camera picked up the colors. Great photos Amanda, thank you! And if you like this one you can also see a similar comparison of colors for Rigel, Betelgeuse and Sirius.

many colorful photos of Sirius, earthsky.org

5-ways to improved UV spectroscopy

If the goal is better UV spectroscopy, we have some news for you. More than 70% of users choose the McPherson Model 234/302 monochromator.

Everybody has a different reason for choosing the McPherson Model 234/302 spectrometer. A few distinct features make it attractive for many applications. All contribute to better basics, like signal-to-noise ratio. All are tailored to detect higher energy photons, beyond visible light and including extreme UV and vacuum ultraviolet spectra. Find detail specifications on the data sheet. We can guarantee performance at short wavelengths because every instrument is tested and calibrated here in the USA.

The Model 234/302 spectrometer is small, robust and at a good price point. That is not all. The Model 234/302 provides you with masterpiece optics. They deliver good spectral purity, practically no scatter and reach the shortest wavelengths. The ability to operate with direct detection CCD detectors or single point detectors is unique too. CCD-array detectors provide wide wavelength range very quickly. Point detectors provide best possible spectral resolution and very fast monitoring of transients. The high performance drive system delivers sharp 0.05 nanometer full-width-half-maximum spectral resolution with the 2400g/mm diffraction grating.

  1. Small and robust. Good price
  2. Masterpiece optics for best performance
  3. Works with point- and CCD-detectors
  4. 10E-6 Torr vacuum tight. Purge capable
  5. Finished to customer request

For applications like HHG spectroscopy, plasma diagnostics, vacuum ultraviolet optical characterization, metrology and calibration the Model 234/302 meets the challenge. This research grade spectrometer has uncompromising performance. It is our pleasure to deliver components as well as system-level solutions. Since it is vacuum-tight, we work with you to make sure coupling flanges, light collection optics, filters, and so on are considered and properly implemented. The Model 234/302 is also available for ultra high vacuum (UHV), metal-sealed, 10E-10 Torr applications. Call or email today to learn how the Model 234/302 fits into your experiments.


Red light therapy

...according to additional research, LED red light therapy has even more health benefits than (potentially) lowering blood pressure. It's been shown to treat acne, reduce certain scarring, heal burns, delay the signs of aging, decrease exercise-induced muscle fatigue, and even prevent against cardiovascular disease, such as heart attacks and strokes. [and related to blood pressure and circulation, erectile function is improved] The science behind this full-body treatment states that just like plants, our skin and other body tissues have the ability to absorb light and turn it into energy, stimulating our body’s natural process to building new proteins and regenerating cells... Fiat lux!

red light bed

LED Lighting and Health

Recently I've ranted to anyone who will listen about LED lighting and how it influences my night vision. I’ve noticed – and it drives me crazy - that when I move from a LED-lit area into darkness my eyes take very long to adjust. From fluorescent (CFL) lighting, slight less long. And from incandescent lamps even less. Automobiles with LED headlights blind oncoming drivers. I can only guess what the reason for this is. Maybe CFL and LED lights, with more pronounced blue emission, de-sensitize or otherwise alter human optic nerves response. Search online I find many references to health effects (positive and negative) related to LED lighting. Here are links to encourage further exploration.

"your body’s energy production involves not just food intake. You also need exposure to certain wavelengths of light in order for your metabolism to function optimally. This is yet another reason why sun exposure is so vitally important for optimal health"

picture of prism with rainbow

Deep UV Sessions

0418 Deep UV Class, April 3 Chelmsford, MA USA.

Prospectus and registration information here.

New hands-on opportunity Spring 2018. Get access to vacuum and purged deep-UV spectrophotometers. Spend time running instruments, learning and practicing best operating procedures. Bring a sample! See what deep UV spectrometers can do and develop skills to realize full potential in your lab.



McPherson advertisement

XUV spectrometers with 64-bit LightField software

McPherson and Princeton Instruments are pleased to announce introduction of a new Add-In for Princeton Instruments’ powerful 64-bit LightField software that seamlessly controls McPherson’s deep UV and soft X-ray spectrometers and Princeton Instruments soft x-ray cameras. This Add-In allows users to keep all the benefits of LightField including easy setup and access to exclusive features like the real-time math engine, SmartSearch, and the virtual optical bench for conveniently managing multiple experimental setups.

aberration corrected spectrometer Rowland circle monochromator aberration corrected spectrometer

Contact McPherson to learn how Princeton Instruments detectors integrate for your application and how LightField controls the hardware. McPherson vacuum compatible instruments work from less than 1 nanometer with a selection of diffraction gratings. McPherson’s flat field, conical dispersion and other specialized solutions are available today, please inquire.


EUVL Workshop

Promoting EUV Lithography via Workshops, Consulting & Education
2018 EUVL Workshop

2018 EUVL Workshop is planned for June 11-14, 2018 at the Center of X-ray Optics (CXRO), LBL, CA. For First call for papers and other information, please visit www.euvlitho.com. Proceedings of the 2017 meeting are available here too.


Color of the year

PANTONE 18-3838 Ultra Violet

happy new year GIF

Some 2018 events:

  • Visit McPherson at booth #2314 CLEO. Laser science to photonic application, May 15-17 San Jose, CA USA
  • 0418 Deep UV Class, April 3 Chelmsford, MA USA.
    New hands-on opportunity Spring 2018. Get access to vacuum and purged deep-UV spectrophotometers. Spend time running instruments, learning and practicing best operating procedures. Bring a sample! See what deep UV spectrometers can do and develop skills to realize full potential in your lab.

EUV Lithography via Workshops, Consulting & Education