Tags: deformable mirror, adaptive optics, Boston University, SLM, spatial light modulator, deep tissue microscopy, Howard Hughes Medical Institute, BMC, imaging systems, two photon, fluorescence
Scattering media can be a real headache if you are looking to achieve high-resolution, deep tissue in vivo images. Without adaptive optics, do not anticipate having the optical control you need to correct for scattering media effectively. But no need to worry, we have a solution.
Since standard Multiphoton Microscopy just wasn’t cutting it, the Cui Lab at Howard Hughes Medical Center pioneered a new technique that Boston University also recently developed, called Superpentation Multi-Photon Microscopy (S-MPM). Each group uses a different optimization scheme but the outcome is the same: The enhanced technique permits active compensation of wavefront aberrations in a scanning beam path through the use of a BMC MEMS Spatial Light Modulator (SLM), allowing for increased depth imaging.
Developed at Boston University and commercialized by Boston Micromachines, the enabling components are the Kilo-SLM and the high speed S-driver. With these components incorporated into the test bed shown in Fig. 1, images of 1 µm diameter fluorescent beads through 280 µm thick mouse skull can be achieved at depths of about 500 µm. The SLM corrected low order spherical aberrations as well as higher order scattering effects. Signal enhancement with higher resolution and contrast were improved by 10x-100x. The optimized SLM phase improves imaging over a field of view of 10-20 µm for samples tested to date with techniques currently in the works to improve upon this.
With 600 nm of stroke and 60 kHz of maximum frame rate, the Kilo-S System comes in a variety of options to fit your needs at a much reduced cost over our standard 1000 channel system. Contact us today for more information on our Kilo-S or any of our other systems!
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.
Tags: deformable mirror, adaptive optics, boston micromachines, turbulence, resolution, response time, CW, pulse, pulse width, peak power, average power, laser beam, SLM, spatial light modulator
In our second installment of this series designed to boil down the questions that need to be answered before selecting the right mirror, we will review some of the past categories with alterations specific to laser beam shaping and introduce a few new ones that pertain only to beam shaping. We plan to focus on pulse shaping applications in our third and final installment of this series.
So you have a beam (CW or pulsed) and you want to control it. Below are the fundamental questions that need to be asked in order to ensure that you’re on the path to obtaining great results in your research or manufacturing application. This list should be combined with Part 1
of this series to get the total picture of what’s needed. I have left out the “pitch” and “response” categories, assuming that you have read the previous installment. Click here
, in case you haven’t.
1) Aperture: How big is your beam?
The size of the wavefront is the first and foremost issue to understand. Some applications have no control over this while others can change the size of their wavefront through the use of some simple focusing optics. Before doing research into your alternatives, you should figure out what your limitations are in relation to this.
2) Control: Phase control? Beam steering?
This will greatly affect the basic type of mirror you will need. For phase control, most modern phase-only mirrors will work, depending on your requirement of resolution (see “2. Resolution” from Part 1 of this series). However, if you get into beam steering, the amount you need to move your beam will greatly affect the type of mirror you need. For example, if you’re trying to move the beam multiple degrees, a fast-steering mirror is probably a good place to start. However, if you’re looking to only make very fine adjustments (milliradians), you can benefit from MEMS-based solutions which are usually referred to as tip-tilt-piston (TTP) devices or piston-tip-tilt, if you’re from one other particular company out there (you know who you are J). Many customers have come to us asking about using our entire mirror surface to steer a beam. For those asking for big angles, we unfortunately have to turn them away, but some want to steer it a very slight angle at high levels of precision and we can do that.
3) Speed: Do you want to make fine adjustments? Are you looking to phase-wrap?
If you’re shaping a beam that is pretty much static, then some low-cost solutions will work. However, if you’re looking to change the profile at high speeds with high precision, MEMS solutions are a great bet. The stroke is sufficient to accomplish phase-wrapping, using our SLM model (segmented surface). With sub-nanometer precision, very precisely-shaped beams are possible.
This is a biggie: If you have a high-powered laser, your options become limited very quickly as most of the very precise devices are a bit fragile as well. Lots of research is being conducted to steer big, powerful lasers and the bulk of the technologies out there fall short due the fact that they are made of thin-film surfaces and temperature-sensitive materials. My recommendation for this is to make sure you know the “big three” properties and contact individual manufacturers to see what their experience is. They are:
1) Peak power (in W/cm2)
2) Average power
3) Pulse width (if applicable)
Most manufacturers probably can’t guarantee much, but if your application has beam characteristics close to some of the data points they have, then it will make you much more comfortable that you won’t be frying mirrors when you fire things up. BMC has a database that is constantly being updated with new experience that we would be happy to discuss. Also, see this paper for the latest published results from our friends at the UCO/Lick Observatory.
As I mentioned before, this is not exhaustive, but if you have these questions answered, your first conversation with either us or one of our competitors will be a pleasant one which will make you more confident of your purchase.
Please chime in and let me know what you think of this series! Again, stay tuned for the final installment where I will talk about pulse-shaping and the different ways that deformable mirror technologies can be used to create the perfect pulse!