Thus lower energy states will have more molecules in them than will higher (excited) energy states. Therefore, the Stokes spectrum will be more intense than the anti-Stokes spectrum.

The Raman effect corresponds, in perturbation theory, to the absorption and subsequent emission of a photon via an intermediate electron state, having a virtual energy level (see also: Feynman diagram). There are three possibilities:

The folks at Incase frame their designs around “protection and mobility to meet the evolving demands of today’s creatives.” Basically, they want to make sure your laptop is safe. And they specifically focus on those creatives who use Apple products—but let’s not get ahead of ourselves.

From a branding perspective, you’ll see a black-on-black Incase logo on the front of the bag and near the strap. You’ll also see little Incase leaves on the edges of the zipper pulls, as well as where the strap attaches to the bag. Personally, we like the look of this logo, so we don’t mind it popping up in various places.

All in all, it’s a nice, simple main compartment. And we’ve liked the versatility of being able to compress this bag down based on what you have inside.

Speaking of handles—there are two pretty nice grab handles on this bag. One at the top and one on the wearer’s right-hand side. They’re nicely padded, have some mesh for breathability, and generally feel good in the hand. That said, they’re a little crinkly.

Towards the back panel is two stretchy mesh pockets, which are great. We kept an Apple Magic Keyboard inside of a neoprene sleeve in one, and a tech pouch in the other.

Ramaneffect isscatteringof

If you’d like a larger quick-access pocket to dump the contents of your pockets into when you’re going through airport security, the front pocket of the EO is a better fit. It has ample room inside and we like the yellow-green interior—it turns on the lights and makes it easy to find your stuff. We also dig that the zipper is hidden beneath a fabric welt, promoting a clean look that goes along so well with the backpack.

The harness system on the Incase EO Travel Backpack is pretty straight forward. The shoulder straps do a decent job, but they’re nothing to write home about.

StimulatedRaman scattering

For high intensity CW (continuous wave) lasers, SRS can be used to produce broad bandwidth spectra. This process can also be seen as a special case of four wave mixing, where the frequencies of the two incident photons are equal and the emitted spectra are found in two bands separated from the incident light by the phonon energies. The initial Raman spectrum is built up with spontaneous emission and is amplified later on. At high pumping levels in long fibers, higher order Raman spectra can be generated by using the Raman spectrum as a new starting point, thereby building a chain of new spectra with decreasing amplitude. The disadvantage of intrinsic noise due to the initial spontaneous process can be overcome by seeding a spectrum at the beginning, or even using a feedback loop like in a resonator to stabilize the process. Since this technology easily fits into the fast evolving fiber laser field and there is demand for transversal coherent high intensity light sources (i.e. broadband telecommunication, imaging applications), Raman amplification and spectrum generation might be widely used in the near future.

Now, keep in mind that the main compartment is what expands and compresses. So, if you have the expansion zipped up and fully compressed, it becomes significantly smaller.

At the top of the bag is a quick-grab pocket that’s about the width of the handle. It’s lined with that same incredibly soft faux-fur found in the laptop sleeve. This pocket is a little bit on the small side—we’ve even had some trouble getting a plus-sized iPhone in it—so it’s much better suited for something like sunglasses.

The inside of the Incase EO Travel Backpack has some great organization going on. Let’s start with the thing you’re probably most excited about—the laptop compartment (Incase does talk it up after all).

Rayleighscattering

The tech area on the Incase EO Travel Backpack is excellent. The zipper on the front opens up horseshoe-style about halfway down the bag. On the front flap towards the bottom, you’ll find two nylon divider pockets. If you keep this bag pretty fully loaded, we think the nylon pockets could be cut—with the outer pocket, main pocket, and two layers of organization, it just gets to be a little bit much. We found ourselves not using these liner pockets very often.

We really like the sternum strap on this bag. It’s pretty much permanently attached, so it won’t get lost. And there’s a bit of elastic that gives the sternum strap some flexibility to move with you when walking. We’ve found that straps designed like this are a lot more comfortable to wear than ones without the elastic. And there’s a strap keeper to help you achieve #DangleFreeExperience.

The interaction of light with matter in a linear regime allows the absorption or simultaneous emission of light precisely matching the difference in energy levels of the interacting electrons.

Overall, we’re digging the look of the Incase Eo Travel Backpack—especially when compressed—but our Instagram audience is pretty split. About 51% gave this bag a thumbs up in the aesthetic department. (Make sure to check us out on Instagram to participate in future polls.)

Taking a look at the back panel, you’ll find two rounded rectangles that do a pretty good job of promoting airflow and breathability. It also looks great as a design element compared to the boxy nature of the rest of the bag. Visually, the back panel is pulled together nicely—and that’s exactly what we’d expect from Incase. As for the functionality, that dreaded swamp back is always hard to avoid, but these panels should help a bit.

The straps themselves are easy to adjust with Duraflex hardware. This harness system is permanently attached to the bag, so there’s no hiding the straps like you can on other packs. While we don’t have an issue with this, it may be a deal-breaker for you.

21.5 in x 15 in x 5 in (54.6 x 38.1 x 12.7 cm)

On the right side, you’ve got a mesh compartment with a neon yellow-green zipper that’s super easy to spot and unzip. It’s pretty much designed like a clamshell suitcase. The cavernous space that opens up inside is ideal for packing cubes. Or, you could fit quite a lot of loose clothing in here if that’s more your style.

When this bag is compressed, it looks pretty slick. Fully expanded, the EO Travel Backpack definitely has a boxy look. It can appear bulky and a bit saggy (more on that in a minute), but functionally, it does a pretty good job standing up on its own. Especially if you pack it right.

The EO Travel Backpack’s main compartment opens up suitcase-style. The left side has a smaller, mesh pocket, which is nice for things like socks, underwear, a small Dopp kit—anything you don’t need quick access to. Above it, you’ll find a small tag that reads “Travel well.” And we enjoy that little reminder.

The lining inside the main compartment has this funky gray and black pattern. This isn’t as much of an issue for visibility here since the bag opens up fully clamshell, but we’re curious what it would have looked like with the yellow-green liner used in the front pocket.

Now, before we move on, we do have a weird little nitpick with the buckles on the Incase EO Travel Backpack. The female side of the buckles acts as a sort of a sheath to cover up the strap on the opposite side. This gives the buckles a clean look, but if the strap is even the slightest bit loose, it obstructs buckling the clip. It’s not a deal-breaker by any means, but these small design details can really make a difference when you’re rushing to catch your train or flight and trying to do things quickly.

We’ve seen a decent amount of marks develop on the TPU—which isn’t surprising. We’ve seen scuff marks like these develop on other bags that use this material, too. So, if you get this bag, you’ll probably experience the same.

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A Raman transition from one state to another, and therefore a Raman shift, can be activated optically only in the presence of non-zero polarizability derivative with respect to the normal coordinate (that is, the vibration or rotation):

Ramanspectroscopy principle

Opposite of the laptop sleeve, you’ll find a liner sleeve where you could put documents, a slim keyboard, or other flat items.

We want to point out that the compression straps can only be unbuckled on the wearer’s right-hand side to get access to the main clamshell. The other side has no buckle—just strap adjusters. When the bag is fully compressed, these compression straps can get very dangly very quickly. We wish they would’ve offered elastic keepers like they did on the sternum strap, but alas.

Raman spectroscopy employs the Raman effect for materials analysis. The frequency of light scattered from a molecule may be changed based on the structural characteristics of the molecular bonds. A monochromatic light source (laser) is required for illumination, and a spectrogram of the scattered light then shows the deviations caused by state changes in the molecule.

Wrapping up the rest of the notable materials on this bag, we have beefy YKK zippers with easy-to-grab zipper pulls. Plus, durable Duraflex plastic hardware on the compression straps, strap adjusters, and sternum strap.

Took this on a trip to Belize, fully expanded and packed out. While the expansion works well, the harness system isn’t our favorite and feels a little cheap.

We really dig how padded the laptop sleeve is. And it’s lined with a fur-like material that’s so soft, you may find yourself petting it for minutes on end. (No? Just us?) Seriously though, it’s great. The only problem with this laptop sleeve is that there’s no false bottom—meaning, your laptop is not suspended within the compartment. If you drop your bag, there’s not much to stop your laptop from hitting the ground, which could lead to some damage. There is some padding on the bottom of the bag, which should help.

At the time of this review, we’ve been testing the Incase EO Travel Backpack in Michigan, Georgia, and Belize. In Michigan, we’ve been using it as a daily driver to bring our essentials to and from work. We found it to be a bit large for everyday use, but not so big that it’s cumbersome (if you keep it compressed to 24L).

Scattering ramanspectroscopy

To expand the EO Travel Backpack fully, simply unzip the compression zipper and completely loosen all four compression straps. When it gets to that point, the bag is pretty wide and boxy. If you don’t have the bag stuffed full, you can use the compression straps to give this thing a slimmer profile. This gives you quite a bit of customizability between 24L and 33L, which we’re big fans of. If 24L is too small but 33L is too big, no problem. Just tighten up the compression straps on the sides and you’re good to go.

At the time of this review, you can pick up the Incase EO Travel Backpack in a few different colorways which come with slightly different materials. We’ve been testing the Black (obviously) which features the materials we mentioned above. The Heather Gray is made with an eco-friendly 300D polyester, while the Navy has 100% polyester on the exterior.

Raman amplification can be obtained by using Stimulated Raman Scattering (SRS), which actually is a combination between a Raman process with stimulated emission. It is interesting for application in telecommunication fibers to amplify inside the standard material with low noise for the amplification process. However, the process requires significant power and thus imposes more stringent limits on the material. The amplification band can be up to 100 nm broad, depending on the availability of allowed photon states.

Scattering ramanprinciple

Disclaimer: We take the measurements of the bag provided by the manufacturer and compare them to the allowance listed on airline websites. This should be used as a guideline rather than a rule. Bags can change size as you pack them out, and every airline's interpretation of compliance is different. Just because a bag is listed as carry-on compliant here doesn't mean that the airline will interpret it that way.

The Raman effect differs from the process of fluorescence. For the latter, the incident light is completely absorbed and the system is transferred to an excited state from which it can go to various lower states only after a certain resonance lifetime. The result of both processes is essentially the same: A photon with the frequency different from that of the incident photon is produced and the molecule is brought to a higher or lower energy level. But the major difference is that the Raman effect can take place for any frequency of the incident light. In contrast to the fluorescence effect, the Raman effect is therefore not a resonant effect.

Another thing to point out on the Incase EO Travel Backpack is that the entire harness system is held on by a #5 YKK zipper. We’re all about YKK zippers, but a No. 5 is pretty measly compared to the larger #10 on the main compartment. If this #5 zipper were to break, the bag would pretty much become useless—except for holding it by the handles. We’re surprised that Incase didn’t opt for a #10 here.

On a trip to Belize, we packed one small and one medium Peak Design Packing Cube—which fit in there pretty much perfectly inside the main compartment—as well as a shoe pouch with some sandals inside and a Blunt Metro Umbrella.

Raman scatteringvs Rayleighscattering

It’s a little big for daily carry, but the thoughtful organization is working out well. And that laptop sleeve is so soft!

The main material on the Incase EO Travel Backpack is a 900D polyester. On the front is a triple-coated TPU. Since this material is not used around the entirety of the bag, it may be more for aesthetic purposes instead of additional weather resistance.

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Overall, we’ve enjoyed testing this bag for both EDC and travel. It’s a solid contender if you’re looking for one bag to do it all.

When light is scattered from an atom or molecule, most photons are elastically scattered (Rayleigh scattering). The scattered photons have the same energy (frequency) and wavelength as the incident photons. However, a small fraction of the scattered light (approximately 1 in 1 million photons) is scattered by an excitation, with the scattered photons having a frequency different from, and usually lower than, the frequency of the incident photons.[1] In a gas, Raman scattering can occur with a change in vibrational, rotational or electronic energy of a molecule (see energy level). Chemists are concerned primarily with the vibrational Raman effect.

We’ve been testing the Incase EO Travel Backpack for the last month in Detroit, Michigan, Atlanta, Georgia, and San Pedro, Belize.

The Incase EO Travel Backpack is a 24L backpack that can be used for your everyday essentials or expanded to 33L to pack for longer trips.

Stimulated Raman transitions are also widely used for manipulating a trapped ion's energy levels, and thus basis qubit states.

Scattering ramanexperiment

Raman spectroscopy is also used in combustion diagnostics. Being a completely non-intrusive technique, it permits the detection of the major species and temperature distribution inside combustors and in flames without any perturbation of the (mainly fluid dynamic and reactive) processes examined.

Compared to similar travel bags, the amount of padding and its density is pretty low. There’s also a noticeable edge to the strap, which can sort of cut into your chest and shoulders if it’s fully loaded with heavy gear. Plus, since there are no load lifters, the bag can be a little saggy. On the plus side, the mesh below the shoulder straps adds some great breathability.

Raman-active vibrations/rotations can be identified by using almost any textbook that treats quantum mechanics or group theory for chemistry. Then, Raman-active modes can be found for molecules or crystals that show symmetry by using the appropriate character table for that symmetry group.

These differences in energy are measured by subtracting the energy of the mono-energetic laser light from the energy of the scattered photons. The absolute value, however, doesn't depend on the process (Stokes or anti-Stokes scattering), because only the energy of the different vibrational levels is of importance. Therefore, the Raman spectrum is symmetric relative to the Rayleigh band. In addition, the intensities of the Raman bands are only dependent on the number of molecules occupying the different vibrational states, when the process began. If the sample is in thermal equilibrium, the relative numbers of molecules in states of different energy will be given by the Boltzmann distribution:

As a one-bag travel pack, the EO is pretty solid as well. The thoughtful pocket layouts make it great to organize all your stuff. But we did notice that some of the design details—like the positioning of the handles and lackluster harness system—were a pain to use in transit.

This organization panel also has liner divider pockets that can house items like a battery bank, snacks, pens, pencils, styluses (styli?), or a small notebook. There’s plenty of space above these liner pockets so you should have room to fit taller items, like a notebook. Plus, depending on how you use these pockets, you may have room for another pouch (like a toiletries bag) in this top area.

The Incase EO Travel Backpack is a streamlined, functional, and versatile bag that expands from 24–33L. But we wish the harness system was more robust.

The laptop compartment opens up clamshell-style. This means, during a security checkpoint, TSA might let you lay it open flat and leave your computer in your bag. We’ve had low success rates in getting through security like this, but your mileage may vary.

You’ll want to keep positioning in mind with these side handles. When the bag is in compressed-mode, they’re pretty grabbable. When the bag is expanded, however, the handle goes way to the front which gives you a floppy, angled carry. Especially if you have a lot of weight inside. Some bag companies skirt this by anchoring the handles at an angle, or they’ll place it right in the center, but that isn’t possible with the compression zipper design Incase chose for this bag. Ultimately, this will just mean a slightly unbalanced carrying experience that’ll be more pronounced when the bag is fully loaded with heavy gear.

The distortion of a molecule in an electric field, and therefore the vibrational Raman cross section, is determined by its polarizability.

In 1922, Indian physicist Chandrasekhara Venkata Raman published his work on the "Molecular Diffraction of Light," the first of a series of investigations with his collaborators which ultimately led to his discovery (on 28 February 1928) of the radiation effect which bears his name. The Raman effect was first reported by C. V. Raman and K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam, in 1928. Raman received the Nobel Prize in 1930 for his work on the scattering of light. In 1998[2] the Raman Effect was designated an ACS National Historical Chemical Landmark in recognition of its significance as a tool for analyzing the composition of liquids, gases, and solids.[3]