import { PasswordStrengthBar } from 'angular2-password-strength-bar';
...
@NgModule({
 ...
   declarations: [
        AppComponent,
        PasswordStrengthBar,
        ...
    ],
    imports: [
      BrowserModule,
      FormsModule,
      ...
 ...
})
export class AppModule {}

@Component({
    selector: 'my-app',
    template: `
  <h3>Angular 2 Password Strength Bar</h3>
    <div>
       <form name="myForm" novalidate>
            <input type="password" class="form-control" id="password" name="password" placeholder="Enter password"
                 [(ngModel)]="account.password" #password="ngModel"
                 minlength="5" maxlength="50" required>
            <angular2-password-strength-bar
                [passwordToCheck]="account.password"
                [barLabel]="barLabel">
            </angular2-password-strength-bar>
        </form>        
    </div>
  `,
})
export class App {
    public account = {
        password: <string>null
    };
    public barLabel: string = "Password strength:";
    // ...
}