Organic polymers breakout into two main categories, Electro-Optical and All-Optical
Electro Optical vs. All-Optical Polymers
Loosely defined, electro-optical polymers can manipulate light, but need the presence of an RF field. However, physicists have proven that it was possible to alter a light wave with another light wave. This became known as the Third-order effect (Chi3) and achieving it would open up endless technological possibilities and make possible new devices like optical transistors that could be essential to manufacturing optical computers. This would herald in a new age of communications and computation technologies that could ultimately promise to replace copper circuitry and electrons with photons moving over fiber optic cable.
Optical Switching Experiment
An experiment was conducted to demonstrate the feasibility of our organic polymer to be deposited between two layers of silicon nitride and when excited by a 1550 nanometer pump laser, they were able to effectuate a phase shift in the light. This was measured and is represented in the chart by the red dotted line representing the sample reflectivity with no pump beam present and the blue showing the phase shift induced when the pump is on.
Electro-Optical and All-Optical Materials
Generally speaking, Lightwave Logic has two classes of chromophores, electro-optical or Second-Order and all-optical or Third-Order. Second-Order materials require an RF field to manipulate light while Third-Order materials use only other light waves to accomplish the same task.
The diagram (left) is a simplification of a Second-Order nonlinear effect. The black line depicts a beam of light entering (absorbed) an electro-optic polymer material before the application of an RF field. The square on the right shows how the application of an electric field which changes the optical properties of the material by altering its index of refraction. The resulting effect is a wave shift. While this is a simplistic example, it is meant to illustrate an electro-optical effect.
In the following example of a Third-Order nonlinear effect, the two yellow light waves are focused on an area of Perkinamine NR™ (one of the company's all-optical organic polymers) sandwiched between layers of Silicon Nitride. The light waves excite the polymer material that creates a virtual holographic mirror. In the next light wave (represented by the red line), a signal wave is sent with a very slight delay, which reflects off the mirror and reverses direction or is switched as indicated by the green line.
This demonstration of a Third-Order effect, known as four-wave mixing was actually conducted by Lehigh University to test the responsive rate of Perkinamine NR™. The response rate refers to the speed at which the material can go from a normal (grounded) state to an excited state, and back which determines how fast switching can take place. This ultimately translates into a data rate because the state of being on-or-off in practice is interpreted as a 1 or a 0-the basis of binary information.
Lehigh University scientists were able to show that Perkinamine NR™ responded at less than a picosecond, equating to a data transmission rate of a terabyte per second.
- It is likely that the actual response rate was even higher because the university had only a picosecond laser (a laser that can pulse light in 1-billionth of a second increments).
Lightwave Logic will shortly begin testing this material using a femtosecond laser capable of pulsing light in one quadrillionth of a second increment (one millionth of one billion). This demonstration underscores the amazing potential of organic polymers to revolutionize communications.City University of New York has subsequently reported thermal stability of this material up to 170C that would allow Perkinamine NR™ to survive CMOS processing.