Question

Light from a blue laser diode has a period of 2.23 x 10^-15 s. Determine the light's wavelength in nm. (1m = 1000000000 nm and the speed of light is 3.00 x 10^8 m/s)

Answer 1

λ = 669.6nm

Step-by-step explanation:

To calculate wavelength, we say

λ = c / f

Where;

λ = wavelength (m)

c = speed of light (3×10^8 m/s)

f = frequency (Hz)

However, T = 1/f

Where;

T = period (s)

f = frequency

Based on the provided information, T = 2.23 x 10^-15 s

f = 1/T

f = 1/2.23 x 10^-15 s

f = 0.4484 × 10^15

f = 4.48 × 10^14 Hz

Since f = 4.48 × 10^14 Hz

λ = c / f

λ = 3×10^8/4.48 × 10^14

λ = 3/4.48 × 10^(8-14)

λ = 0.6696 × 10^(8-14)

λ = 0.6696 × 10^-6

λ = 669.6 × 10^-9m

λ = 669.6nm