# Optical Tweezers in the Ray Optics Regime

• JamesB
In summary: The only information given is the net reflection angle of the ray and the wavelength of the photon. Therefore, it is not possible to solve for the total number of photons.
JamesB

## Homework Statement

Consider an optical tweezer operated in the ray optics regime as shown in Figure. Net reflection angle of the ray shown in Figure is θ = 10◦ (See Figure). Since more photons take the thick ray than the thin ray, a net force of F = 1 pN is exerted on the sphere toward the left. The wavelength of the photon is λ = 1000 nm. Let Nthick and Nthin be the number of photons per second in the thick and thin ray, respectively. Find ∆N = Nthick − Nthin.

p = h/λ
E = hf
f = c/λ
F = dp/dt

## The Attempt at a Solution

I feel like there is not enough information given in this problem to solve for the total number of photons.
I know in the Ray Optics Regime:

Fscat = (nm*P)/c(1+Rcos(2ΘR)-TF2(cos(2ΘR-2ΘT)+Rcos(2ΘR)/1 + R2 + 2Rcos(2ΘT))

Fgrad = (nm*P)/c(1+Rsin(2ΘR)-TF2(sin(2ΘR-2ΘT)+Rcos(2ΘR)/1 + R2 + 2Rcos(2ΘT))

I am not sure with the given information how to manipulate these equations to determine the solution or if I am overthinking. Please Help!

A:The number of photons is determined by the power incident on the sphere, which is not given. You can try to calculate it, but without knowing the source intensity and distance from the sphere, it's impossible to do.

## 1. What are optical tweezers in the ray optics regime?

Optical tweezers in the ray optics regime are a type of scientific instrument that uses focused laser beams to trap and manipulate microscopic particles. This technique is based on the principles of ray optics, where light is treated as a collection of rays that can be bent and focused using lenses.

## 2. How do optical tweezers work?

Optical tweezers work by using a laser beam to create a gradient of light intensity. This gradient creates a force on the microscopic particles, pushing them towards the center of the beam. By precisely controlling the position and intensity of the laser beam, researchers can manipulate the trapped particles in three dimensions.

## 3. What kind of particles can be trapped using optical tweezers?

Optical tweezers can trap a variety of particles, including biological cells, viruses, and nanoparticles. The particles must be small enough to be affected by the gradient of light intensity and must have a different refractive index than the surrounding medium in order to be trapped.

## 4. What are the applications of optical tweezers in the ray optics regime?

Optical tweezers have a wide range of applications in scientific research, including studying the mechanical properties of cells, measuring forces at the microscopic level, and manipulating individual molecules. They are also used in fields such as biophysics, microbiology, and nanotechnology.

## 5. What are the advantages of using optical tweezers in the ray optics regime?

Optical tweezers offer many advantages over other manipulation techniques. They are non-invasive, allowing for the study of delicate biological samples without causing damage. They also have high precision and can manipulate particles in three dimensions, making them a powerful tool for studying and manipulating small-scale systems.

• Optics
Replies
3
Views
2K
• Introductory Physics Homework Help
Replies
12
Views
1K
• Introductory Physics Homework Help
Replies
13
Views
2K
• Introductory Physics Homework Help
Replies
1
Views
2K
• Introductory Physics Homework Help
Replies
3
Views
1K
• Introductory Physics Homework Help
Replies
2
Views
5K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
7K
• Introductory Physics Homework Help
Replies
1
Views
4K
• Quantum Physics
Replies
8
Views
1K