Filtering the signal from noise

I am having a signal of 5 Seconds and total number of samples are 1000000 which are coming from an Laser Diode and I want to seperate signals of 1Hz frequency which are mixed with noise from various source by which filter and how to extract this signals ?

As I am new to matlab signal processing don't know how to do it please help !!!

[KALYAN ACHARJYA]

@Rohan Requested to read about filters like this, there are numerous types of filters.

I am just provided the example, how you can use filters, not suggesting to use low pass filters in your case.

[Rohan Mehta]

I tried but the error is

Undefined function 'lowpass' for input arguments of type 'double'.

[Raj]

I don't think low pass filters will work here. Your requirement is to extract only 1Hz signal from the noisy signal. Looks like you need a Bandpass filter with a very narrow pass band around 1Hz. See here.

[Rohan Mehta]

Same error for bandpass filter

Undefined function 'bandpass' for input arguments of type 'double'.

[Raj]

Looks like you don't have signal processing toolbox installed. Go by the old design way and design a transfer function for bandpass filter. Good luck.