Polarize (verb)

1. Cause (a group, community, or society) to divide into two sharply contrasting groups, typically along ideological lines.
2. Cause (light or other electromagnetic waves) to vibrate in a particular direction, typically as a result of passing through a polarizing filter.
3. Divide or cause to divide into two sharply contrasting groups or sets of opinions or beliefs.

Origin:

Mid 19th century: from pole + -ize.

Examples:

1. The election has polarized the country along ideological lines.
2. The issue of immigration has polarized the community.
3. The polarizing filter allows only vertically polarized light to pass through.
4. The argument polarised the crowd into two sides.
5. The political situation polarised the nation into two factions.