(1) If an officer or enlisted person who, prior to the effective date of this section, has retired under section 49 and has served not less than 20 years of full-time employment on actual state duty in support of the full-time operation of the state military establishment, dies and leaves a surviving spouse, the surviving spouse shall be entitled to 50% of the retirement pay which the officer or enlisted person was receiving prior to his or her death. The surviving spouse shall receive the benefit provided in this section until his or her death.

    (2) “Surviving spouse” means, for purposes of this section, a person to whom an officer or enlisted person was married at the time of his or her death.