If you've been hiding out in the lab, constantly checking your March Madness bracket, or escaping the cold to find any ounce of warmth (like me!), chances are you may have missed some exciting news. March turned out to be quite a busy month in the Adaptive Optics world, so here’s what you missed:
1. Exoplanet imaging in under a minute
At the recent AAAS 2015 annual meeting, Bruce Macintosh from Stanford University and Principal Investigator for the Gemini Planet Imager (GPI), discussed that there are over 1,000 confirmed planets due to the help of Adaptive Optics. In order to start really understanding a planet and its characteristics, you need to look at the composition of its atmosphere. Astronomers have relied heavily on the adaptive optics technique, allowing for distortion correction of the atmosphere using a deformable mirror. This has had proven success in regards to GPI, which uses a BMC deformable mirror (4K-DM), as part of its adaptive optics system. It can image planets in about a minute, which used to take up to an hour! GPI recently imaged the HR8799 star system, with three orbiting planets. Since November 2013, GPI has imaged 600 stars and identified 50-60 new planets.
2. 2nd quadruple star system discovered
More exciting news from the Astronomy world was the discovery of a massive planet with a quadruple star system only 125 light-years from Earth. Discovered by the Jet Propulsion Laboratory, they were able to detect the fourth star after fitting the telescopes at the Palomar Observatory with a Robo-AO adaptive optics system. Utilizing the AO technique allowed astronomers to pick up on the faint star that couldn’t be seen before. Below is a diagram illustrating the discovered Ari 30 alongside its pair in a binary systems. Before this detection, only one other planet in a quadruple star system had been discovered before. More sightings are being predicted as exoplanets are found, with the help of Adaptive Optics systems of course!
(Photo credit: NASA / JPL-Caltech)
3. The most valuable brains
Congratulations to Scientists Winfried Denk, Arthur Konnerth, Karel Svoboda and David Tank for being awarded the world’s most valuable neuroscience prize, The Brain Prize, for the invention and development of two-photon microscopy! Two-photon microscopy is helping researchers to understand the human brain and how its networks process information, such as nerve cell communication. It has also enabled the study of nerve cells that control vision, hearing and movement. Recent work has been carried out to implement adaptive optics systems on two-photon microscope systems around the word, including locations such as the Howard Hughes Medical Institute, Institute Langevin at CNRS and Boston University. Standing on the shoulders of giants to improve imaging of the brain with AO!
Now that you are caught up with some of the biggest achievements using Adaptive Optics this past month, check out all of our deformable mirror products that are used in AO instruments like GPI on our website. Questions? Looking for a deformable mirror that will fit your needs? Contact BMC here.
AO 101 Whitepaper
Looking to learn more about Adaptive Optics? Download our whitepaper to learn the fundamentals and how our customers are implemeting our DM's into their AO systems.
Tags: deformable mirror, adaptive optics, boston micromachines, Boston University, pulse, pulse width, peak power, laser beam, laser science, BMC, laser pulse shaping, ultrafast lasers, laser pulse compression, Mirrors
About half of our customers use our deformable mirrors for laser applications, such as beam shaping or steering. We get a lot of questions pertaining to laser power and handling for both our deformable mirrors and modulators. Below is a summary of the guidelines we use when discussing our technolgy.
The most important specification to note immediately if you are working with lasers is the damage threshold of our DM's. There are two mechanisms of failure to consider: mirror damage due to heating and coating delamination. The first failure mode is largely governed by the average power experienced by the DM. The rule of thumb that we follow is maximum average power of 20W/cm². For the second failure mode, the peak energy is of greatest concern. In this case, the threshold that we use is that of a standard thin-film gold metallic coating, in this case, 0.4J/cm². Depending on the DM system, the calculations may be slightly different. In order to ensure a DM is suitable for your application, we typically need to know as many of the following properties as possible: the pulse width of the laser, peak power, frequency, wavelength and beam size. This last pameter will help to determine which aperture size is required and if you need to change your beam size at all. Additional information on laser power can be found on our previous blog here.
From a power threshold standpoint, our modulator technology works similarly to our deformable mirror technology. However, it may have a slightly lower damage threshold due to the fact that the exposed surface is a thin layer of silicon nitride as opposed to the thicker polysilicon surface used for our deformable mirrors. Honestly, we do not have much experience testing the devices. If you are interested in carrying out testing, we would be glad to lend you some modulators to test.
If you are interested in learning more about customers' experience with high-power lasers used on our DM's, please click here to read Andrew Norton's paper on laser test performed using our DMs. Also, please visit our website or contact us for questions or additional information on how to obtain a device for testing.
Tags: deformable mirror, adaptive optics, boston micromachines, retinal imaging, free-space communication, modulating retroreflector, segmented, laser beam, SLM, spatial light modulator, deep tissue microscopy, SPIE, BMC, imaging systems, Photonics West, microscopy, two photon, optical chopper, optical modulator, chopper, Adaptive Optics Scanning Laser Ohphthalmoscope, Joslin Diabetes Center, Mirrors
Just a few weeks ago we arrived back from the Photonics West 2014 exhibition and conference in San Francisco, CA. I wanted to share details and further observations on the show for those present at the show and those not being able to attend this year.
For the first time we made the decision to also attend the BiOS exhibition for the few days prior to PWest. Not being quite sure what to expect for booth traffic, especially since it conflicted with the superbowl, we still generated a good amount of interest for the smaller show. Our main presentations focused on our new adaptive optics-enhanced scanning laser ophthamoscope (AOSLO), the Apaeros Retinal Imaging System, which includes our Multi-DM, and the Superpenetration Multiphoton Microscopy technique, which is enabled by our Kilo-SLM and high speed S-Driver. Although both exhibits generated respectable notice and positive feedback, most people were familiar with the Superpentration Multiphoton work being done. Either wanting to try two-photon microscopy themselves or already in the process of doing so, our Kilo-SLM paired with our high speed S-driver presented data that was intriguing to most.
After wrapping up BiOS, we headed to the opposite side of the South hall at the Moscone Center for a larger booth setup for PWest. Here we had our entire mirror family on display, as well as live demonstrations of the Reflective Optical Chopper and Wavefront Sensorless Adaptive Optics Demonstrator for Beam Shaping (WSAOD-B). For this part of the exhibition, I would say our deformable mirrors produced the most attention, most likely due to our wide assortment of shapes and actuator counts up to 4092. The WSAOD-B live demonstration did generate a great deal of attention, as most people are unaware of how sensorless AO works. Besides our deformable mirror line, I would still say the Multiphoton Microscopy overview was initiating even further interest here as well.
Overall BMC had a great show and it seemed well worth it to expand our exhibit onto BiOS beforehand. Although this was my first time attending the show, I noticed every inch of space at PWest being used for exhibitor tables and booths, even setting up in front of the bathrooms! I hope to see PWest advance even larger, maybe one day expanding to its third space, West Hall. I look forward to next year’s show and hope to reconnect with you all again throughout the year.
If you were not able to attend the show and would like any information on the products mentioned, please visit our website and download our whitepapers.
Happy New Year! Hope everyone had a great holiday and is staying warm.
To continue addressing our FAQ's, another recurring question BMC recieves is on the flatness of our deformable mirrors. The figure below shows an unpowered BMC DM and a flattened BMC DM.
The surface figure of our unpowered deformable mirrors has a low-order surface bow. The amount of stroke needed to flatten the DM is between .5 µm and 1 µm, depending on the model. We can guarantee that the stroke needed to flatten the deformable mirror will not exceed this amount and tends to be lower for the lower stroke devices.
However, researchers in the past have been able to achieve flattening the wavefront without using up any stroke on the DM. If you are able to include additional optics into your setup, the low order bow can be taken out with static optics. Just something to keep in mind as you are designing your system and trying to determine how much stroke is required to achieve your wavefront correction needs.
If you have any additional questions in regards to the flatness of our mirrors or are interested in seeing what the typical unpowered surface figure is, please contact us at email@example.com or visit us online at www.bostonmicromachines.com
Over the past couple of months we have been receiving an assortment of questions in regards to our products. We thought it would be a good idea to share the more popular questions and answers as they stream in to keep everyone updated.
One question that tends to be asked quite often is the reflectivity our deformable mirrors can achieve. This depends on a couple of factors such as mirror coating, protective window AR coating and the wavelength of the light.
We offer gold, aluminum and protected silver coating on almost all of our deformable mirrors. When selecting a coating, you should pay particular attention to the wavelength(s) of light you use. The BMC DM Coating Reflectivity chart to the right illustrates the reflectivity of each of our standard coatings.
Our standard windows with AR coating are BK-7. We offer a few options, depending on which size mirror you select. For our smaller DMs, we offer the standard coatings from Thorlabs as well as a few more versatile options. You may choose either uncoated, 350-700nm, 650-1050nm or 1050-1620nm. We also offer a 400-1100nm window and 550-2400nm, the latter for an additional cost. For our larger DMs, various coating options are available. We do offer customizable options for an extra fee, so please contact us with your specifications if you require this.
The N-BK7 Broadband Antireflection Coatings chart from Thorlabs below depicts the percentage of light lost for each AR coated window. Similar curves are available for our other coatings.
If you are looking for additional information on our standard windows, please visit our friends at Thorlabs online. If you have any further questions on the reflectivity of our mirrors, click here to send us an e-mail or visit us online at www.bostonmicromachines.com