In HoloLens 1, holograms were created by reflecting images from a screen in the headset into specially made lenses for red, blue and green light waves. Those light waves were then beamed into the back of your eyes, where your brain would create the final image.

The device has a mirror known as a MEMS that moves fast enough to create the illusion of a screen in space. The MEMS creates 120 of these screens each second, filtered to the eye through lenses in the headset. The result is smooth movements, more-believable animations and quick response if you move your head

Hololens 2

In <a href="https://www.wevolver.com/wevolver.staff/hololens.gen.1/" rel="noopener noreferrer" target="_blank">HoloLens 1</a>, holograms were created by reflecting images from a screen in the headset into specially made lenses for red, blue and green light waves. Those light waves were then beamed into the back of your eyes, where your brain would create the final image.The device has a mirror known as a MEMS that moves fast enough to create the illusion of a screen in space. The MEMS creates 120 of these screens each second, filtered to the eye through lenses in the headset. The result is smooth movements, more-believable animations and quick response if you move your head.There’s an 8-megapixel front-facing camera for video conferencing, and it’s capable of full 6 degrees of tracking, and it also uses USB-C to charge.The device has a time-of-flight depth sensor, AI, and semantic understanding, and eye-tracking sensors that allows the user to manipulate holograms more naturally, which also means less learning curve to use the device.HoloLens has speakers on the side, and you can lift the visor, just like a welding mask, to get to the real world without removing the headset.&nbsp;The headset is made of carbon fiber and the computing parts are on the back to make it more comfortable to wear, as the center of gravity is now in the middle of the head.HoloLens 2 includes a Qualcomm Snapdragon 850 chip, the same technology powering most flagship phones on the market. And it more than doubles the field of view while maintain 47 pixels per degree of sight.

Describes the technology, shows use-cases, and applications for the Hololens. 

Hololens 2 on Microsoft website.

Display

Optics

Resolution

Holographic Density

Eye-based Rendering

Sensors & Audio

Depth

Camera

Microphone Array

Speakers

Compute & Connectivity

SoC (system on a chip)

Wi-Fi

Bluetooth

Power

Battery Life

Charging

Thermals

HoloLens 2 is a pair of mixed reality smartglasses that has twice the field of view than HoloLens Gen1, while maintaining the 47 pixels-per-degree of sight and providing 2K displays per eye. HoloLens 2 can work offline, and it can connect to any cloud.

Display
Optics	see-through holographic lenses (waveguides)
Resolution	2	k 3:2 light engines
Holographic Density	2.5	k radiants (light points per radian)
Eye-based Rendering	display optimization for 3D eye position
Sensors & Audio